DB's ending

[ABED]

First, he was several hundreds of years old and he didn't step aside, he had been surpassed, but retired gracefully.

[Basaku]

Gohan isn't the protagonist, and he's only introduced 1/3 of the way through the series. It's about Goku, and his ethos was never about being a responsible fighter and a protector. Future Trunks is the closest thing to a Superhero, but it's not that kind of show. It's about martial artists who are out to become better martial artists. It's not about superheroes saving the world.

It doesn't matter he's introduced 1/3rd throughout the series, he's a massive part of it to the point of nearly overtaking lead role. Future Trunks and his themes are huge part of the franchise too, made even bigger with Super. You can't dismiss these things being big part of the franchise so an ending to embody and reflect on them too, not just the 'training for the sake of training' aspect.

[ABED]

AN important character, but not THE most important character. Future Trunks's themes aren't all that important if he doesn't put up much of a fight when tells him he plans on fighting them. Goku and Co. intentionally lets Dr. Gero complete the cyborgs for the sake of a fight. Trunks has a time machine, and despite knowing Goku's plan, he doesn't go about stopping it. And no, Goku didn't become more "selfish" in the Cell arc, he also let Vegeta and Piccolo go for the same reason - for the sake of a better fight. Gohan doesn't put up a fight when Goku says he's going to fight the cyborgs.

I can't dismiss those things, but you can somehow dismiss everything I and other commenters have posted and even Toriyama's statement on this subject.

“While he does end up saving everyone as a result of that, he himself at least has a very pure sincerity about ‘wanting to become stronger.’ What I wanted to depict the most was the sense that he might not be a good guy at all, although he does do good things as a result.”

[floofychan333]

I think Dragon Ball should end with Goku dying for once and for all of natural causes. I don't want there to be any "passing the torch" moment where Goku's dying words are "Pan, you have to fill my shoes" or whatever because that will just set up a new series at some point that can use it as a springboard. Goku just dies, plain and simple, but he's ready to go. Maybe he'll be really old and just realize his time has come and he's accomplished everything he wanted to.