Supposing that things never went downhill in Trunks' timeline...?

[theherodjl]

....what would that mean exactly for the main timeline? Would it have been an inverse in which things totally go south for the Earth in the main timeline? Or would it have little-to-no bearing on it and there wouldn't be an erasure of one timeline or the other by either of the Zenos? It always seemed that things had to go 'wrong' in Trunks' timeline in order for things to go 'right' for the main timeline, what implication would there be if it never started in the first place though?

[TobyS]

....what would that mean exactly for the main timeline? Would it have been an inverse in which things totally go south for the Earth in the main timeline? Or would it have little-to-no bearing on it and there wouldn't be an erasure of one timeline or the other by either of the Zenos? It always seemed that things had to go 'wrong' in Trunks' timeline in order for things to go 'right' for the main timeline, what implication would there be if it never started in the first place though?

Hmm well it depends how right things go in Trunks timeline.

If you mean Goku not dying then that's one thing.

If you mean the Cell arc then killing the androids forces Cell back in time, unless things go so right they stop Cell stealing the machine.

Trunks does not create the unseen timeline but Cell would create Cells timeline, but it might be a tadge different due to butterfly effect.

Goku not being dead might mean his end at the hands of 16, but if he's dead it depends on how the androids react and if he runs into Cell.

Regarding the Black arc, Zamasu chose it because of there being no Beerus, and a "sinner" Trunks to punish and train Black on.

Black may end up chosing U12 guys timeline or the Unseen Timeline, or Cells Timeline to start his rampage.

All we know about the other timelines is they are weaker than the old main timeline Black stole Gokus body from.

It depends if he can be stopped before he levels up too much.

[theherodjl]

Alright, imagine that Trunks' timeline goes perfectly then.
Goku doesn't die as the heart virus never afflicts him.
The Androids don't get the jump on the Z Senshi as Gero is somehow found out ahead of time, his main lab & underground lab both getting destroyed before the Androids or Cell can be created.
Babidi comes to Earth later but doesn't have Dabura with him as his access to the demon realm had been cutoff by Shin & Kibito beforehand.
Zamasu's plan is discovered by Rumsshi & Cus and he is dealt with accordingly.
Had these things gone down in Trunks' future, what would it mean for the main timeline? Would it be a positive butterfly effect and negate bad things for the main timeline also? Might it doom the main timeline? Or would it still end up going more or less the same way just with some differences?

[TobyS]

Alright, imagine that Trunks' timeline goes perfectly then.
Goku doesn't die as the heart virus never afflicts him.
The Androids don't get the jump on the Z Senshi as Gero is somehow found out ahead of time, his main lab & underground lab both getting destroyed before the Androids or Cell can be created.
Babidi comes to Earth later but doesn't have Dabura with him as his access to the demon realm had been cutoff by Shin & Kibito beforehand.
Zamasu's plan is discovered by Rumsshi & Cus and he is dealt with accordingly.
Had these things gone down in Trunks' future, what would it mean for the main timeline? Would it be a positive butterfly effect and negate bad things for the main timeline also? Might it doom the main timeline? Or would it still end up going more or less the same way just with some differences?

Maybe, Granollah probably never finds out about the saiyans, Freeza probably isn't revived if Goku and Vegeta are still on earth. Moro dies in prison.

Eventually Zeno might decide to erase the universe but not nearly as soon as he has no alt counterpart to discuss it with.

Depends on the Daima villian, perhaps he kills everyone as they are weaker.

[SupremeKai25]

You are basically talking from a Doylist perspective and asking to rewrite the story from Toriyama's perspective.

In the actual universe, from Watsonian perspective, Trunks' timeline was destined and doomed. It was the original course of history, the original direction. As Black and Zamasu point out in the time travel arc, the history demanded that Goku succumb to the heart virus. That is the original history. Goku dead by the heart virus, before Goten is born and when Gohan is still a kid. That is the original course of history in the Dragon Ball world. Normally, you can't alter that.

If you alter that, you get separate timelines. Even if somehow the FT timeline was the "happy timeline", that would defy history. Because the history was not supposed to be "Happy". History demanded that the Androids wreck and kill everything (I'm not counting Black and Zamasu's attack, since they, too, are part of the altered history aka they never would have existed in their current incarnations if Goku died like history dictated).

For every happy timeline, there must be a doomed one. This "happy" FT timeline would be an altered one, the result of a doomed one.

Which is what we saw in Canon, after all. The new timeline Trunks and Mai go to is a "happy" version of the original, doomed FT timeline, where Black and Zamasu's plans are thwarted before they are even placed in motion.

In other words, there is no instance where FT timeline is happy. It was doomed from the start. It is what history dictated. You can defy history, but only through time travel, and that creates a separate timeline.

From a Doylist perspective, you could ask why Toriyama wanted the original timeline to be so doom and dark.

[Zephyr]

Alright, imagine that Trunks' timeline goes perfectly then.
Goku doesn't die as the heart virus never afflicts him.
The Androids don't get the jump on the Z Senshi as Gero is somehow found out ahead of time, his main lab & underground lab both getting destroyed before the Androids or Cell can be created.
Babidi comes to Earth later but doesn't have Dabura with him as his access to the demon realm had been cutoff by Shin & Kibito beforehand.
Zamasu's plan is discovered by Rumsshi & Cus and he is dealt with accordingly.
Had these things gone down in Trunks' future, what would it mean for the main timeline? Would it be a positive butterfly effect and negate bad things for the main timeline also? Might it doom the main timeline? Or would it still end up going more or less the same way just with some differences?

If Goku never dies from the heart virus and Earth's greatest martial artists (including Piccolo and God) are not killed off by Gero's creations, then Bulma never builds a time machine. The "main timeline" is never created. Gohan possibly never becomes a Super Saiyan, having no further need to divert attention away from his scholarly pursuits. Without the threat of the Androids and Cell, it's unclear if Goku and Vegeta would have been motivated sufficiently to find a level beyond the Super Saiyan, so it's unclear if Super Saiyan 2 would ever be discovered, let alone Super Saiyan 3. There is no Cell Game, so Mr. Satan is never regarded by the population as Earth's savior. Kuririn never gets married to #18.

Goten may still be born, and he and Trunks would likely still become friends, sparring together, and becoming Super Saiyans. If Bobbidi comes to Earth without Dabura, he'd probably be taken care of pretty handily. Vegeta has no reason to give in to Bobbidi's spell, since he wasn't promised and then possibly denied a match against Goku during the latter's 'one day' on Earth. So Boo probably doesn't get revived. Does Gohan still meet Videl? Is Pan born? Unclear.

Beerus would likely still wake up and look for the Super Saiyan God, which would eventually lead to Goku having the ritual performed on him. I see no reason why Whis wouldn't still end up training Goku and Vegeta, with the pair discovering Super Saiyan Blue. Freeza would still be revived, and warned that Goku has tangled with Beerus, motivating Freeza to train.

Super would probably proceed as normal, with Goku and Hit fighting at the tournament, which Zamasu would see and be upset by. This would motivate him to use the Super Dragon Balls and swap bodies with Goku, before killing him. But the question then becomes, what happens next? There is no "timeline where Beerus died" for him to swap over to, so I imagine he might try to kill Kaioshin in order to eliminate Beerus for his plan to be kicked off. From there, it's hard to say what goes down. Either way, he wouldn't have a second self to turn immortal and fuse with, so I doubt things would ultimately go so far south. I imagine that after some bullshit, Goku would get revived and returned to his body.

Past this, we would still probably eventually get the Tournament of Power, with a very different roster. No Gohan, no #17, no #18. Maybe Goten, Trunks, and Yamcha in their places? With no #17, it's unclear how the Tournament of Power would be resolved, but I expect Freeza to be the team player he was all the same, and get revived afterwards. If Freeza gets revived, then Broli shows up on Earth. With no fusion learned by Goku in the afterlife, there's no Gogeta to resolve things. That might result in Goku being pushed far enough for Ultra Instinct to activate, which I think would be sufficient to defeat Broli all the same, with Cheelai wishing him away to Vampa still. From there, it's really unclear what happens. What would Carmine and Magenta be planning? Even if they make the Gammas, there's likely no Cell Max happening, Gohan would be a non-factor, especially if there is no Pan to kidnap. As there was no Boo to die, there is no Oob at the 28th Tenkaichi Budokai.

If we include GT possibilities, then there is no Goku sparring with Oob at God's temple when Pilaf shows up and uses the black starred Dragon Balls. So Goku does not become a child. It's unclear if anybody realizes that the balls have been used, or what that means, or if Kaio informs them of what happened. If he doesn't, then the Earth blows up in a year with nobody realizing what happened. That might be it! If Kaio does inform them of what happened, then Goku, Trunks, and Goten go into space to find the balls. They would have eventually reached M2, and probably had an initial tangle with Baby, who would still likely beat them back to Earth and take over. Without Pan, it's unclear if Goku becomes a Super Saiyan 4, and it's unclear how they would have defeated Baby. But still having a card like the Genki Dama, I think they would have managed to defeat him.

Without all of the wishes of the Cell and Boo arcs, the Dragon Balls might not crack as soon as they did. Which means that the barrier between the living realm and the afterlife wouldn't weaken, unleashing dead villains from the past, as soon as it did. No #17 being made means no Super 17, so even if Super Saiyan 4 never happens they would be fine, when the barrier does eventually weaken. The Evil Dragons would also happen at some point later than it did. Would they be able to win against them? Would Goku have Super Saiyan 4 yet? Unclear, but there is still the universal Genki Dama.

[Koitsukai]

Alright, imagine that Trunks' timeline goes perfectly then.
Goku doesn't die as the heart virus never afflicts him.
The Androids don't get the jump on the Z Senshi as Gero is somehow found out ahead of time, his main lab & underground lab both getting destroyed before the Androids or Cell can be created.
Babidi comes to Earth later but doesn't have Dabura with him as his access to the demon realm had been cutoff by Shin & Kibito beforehand.
Zamasu's plan is discovered by Rumsshi & Cus and he is dealt with accordingly.
Had these things gone down in Trunks' future, what would it mean for the main timeline? Would it be a positive butterfly effect and negate bad things for the main timeline also? Might it doom the main timeline? Or would it still end up going more or less the same way just with some differences?

If Goku never dies from the heart virus and Earth's greatest martial artists (including Piccolo and God) are not killed off by Gero's creations, then Bulma never builds a time machine. The "main timeline" is never created. Gohan possibly never becomes a Super Saiyan, having no further need to divert attention away from his scholarly pursuits. Without the threat of the Androids and Cell, it's unclear if Goku and Vegeta would have been motivated sufficiently to find a level beyond the Super Saiyan, so it's unclear if Super Saiyan 2 would ever be discovered, let alone Super Saiyan 3. There is no Cell Game, so Mr. Satan is never regarded by the population as Earth's savior. Kuririn never gets married to #18.

Goten may still be born, and he and Trunks would likely still become friends, sparring together, and becoming Super Saiyans. If Bobbidi comes to Earth without Dabura, he'd probably be taken care of pretty handily. Vegeta has no reason to give in to Bobbidi's spell, since he wasn't promised and then possibly denied a match against Goku during the latter's 'one day' on Earth. So Boo probably doesn't get revived. Does Gohan still meet Videl? Is Pan born? Unclear.

Beerus would likely still wake up and look for the Super Saiyan God, which would eventually lead to Goku having the ritual performed on him. I see no reason why Whis wouldn't still end up training Goku and Vegeta, with the pair discovering Super Saiyan Blue. Freeza would still be revived, and warned that Goku has tangled with Beerus, motivating Freeza to train.

Super would probably proceed as normal, with Goku and Hit fighting at the tournament, which Zamasu would see and be upset by. This would motivate him to use the Super Dragon Balls and swap bodies with Goku, before killing him. But the question then becomes, what happens next? There is no "timeline where Beerus died" for him to swap over to, so I imagine he might try to kill Kaioshin in order to eliminate Beerus for his plan to be kicked off. From there, it's hard to say what goes down. Either way, he wouldn't have a second self to turn immortal and fuse with, so I doubt things would ultimately go so far south. I imagine that after some bullshit, Goku would get revived and returned to his body.

Past this, we would still probably eventually get the Tournament of Power, with a very different roster. No Gohan, no #17, no #18. Maybe Goten, Trunks, and Yamcha in their places? With no #17, it's unclear how the Tournament of Power would be resolved, but I expect Freeza to be the team player he was all the same, and get revived afterwards. If Freeza gets revived, then Broli shows up on Earth. With no fusion learned by Goku in the afterlife, there's no Gogeta to resolve things. That might result in Goku being pushed far enough for Ultra Instinct to activate, which I think would be sufficient to defeat Broli all the same, with Cheelai wishing him away to Vampa still. From there, it's really unclear what happens. What would Carmine and Magenta be planning? Even if they make the Gammas, there's likely no Cell Max happening, Gohan would be a non-factor, especially if there is no Pan to kidnap. As there was no Boo to die, there is no Oob at the 28th Tenkaichi Budokai.

If we include GT possibilities, then there is no Goku sparring with Oob at God's temple when Pilaf shows up and uses the black starred Dragon Balls. So Goku does not become a child. It's unclear if anybody realizes that the balls have been used, or what that means, or if Kaio informs them of what happened. If he doesn't, then the Earth blows up in a year with nobody realizing what happened. That might be it! If Kaio does inform them of what happened, then Goku, Trunks, and Goten go into space to find the balls. They would have eventually reached M2, and probably had an initial tangle with Baby, who would still likely beat them back to Earth and take over. Without Pan, it's unclear if Goku becomes a Super Saiyan 4, and it's unclear how they would have defeated Baby. But still having a card like the Genki Dama, I think they would have managed to defeat him.

Without all of the wishes of the Cell and Boo arcs, the Dragon Balls might not crack as soon as they did. Which means that the barrier between the living realm and the afterlife wouldn't weaken, unleashing dead villains from the past, as soon as it did. No #17 being made means no Super 17, so even if Super Saiyan 4 never happens they would be fine, when the barrier does eventually weaken. The Evil Dragons would also happen at some point later than it did. Would they be able to win against them? Would Goku have Super Saiyan 4 yet? Unclear, but there is still the universal Genki Dama.

Good answer. Makes me wonder if there's an alternative timeline in our real world where people actually got to witness that detour of the franchise. Maybe SS is the only form ever seen by those weirdos.
I wonder what the Z movies be like over there. Probably, after the Cooler movies, they got the Z Broly movies and that was it.