Vegeta's trainings is just bad

[Kishido]

Ever since the Cell saga... maybe even before but I will start from here

Vegeta goes to RoSaT... Comes out and get some subpar muscle form.

Goku goes in... Comes out with FPSSJ and Gohan even more. Vegeta goes RoSaT again... Gains nothing

Buu saga

While not bad that he gained Super Saiyan 2 he still needed Majin to be on par with Goku... But Goku also gained Super Saiyan 3.

Super

Amazing that he learned god ki under Whis... But Goku goes BAAAAM SSB Kaioken.

After it his trainings sucks. Goes RoSaT at Zamasu arcs comes out stronger but hasn't gained anything noticeable compared to Goku.

Now in the the ToP he goes into RoSaT as only character as well... Let us see what he gained but I doubt it will be better than Goku's new transformation... the Goku who was in the meantime searching for people instead of being in RoSaT.

You can even take Trunks and Gohan into account... But well they are asspull hybrids wit no time for a proper built up.

PS
You can even take Super manga and GT into it... Manga Goku mastered SSB and learned Hakai. Even Vegeta realized it

Not even talking about GT where after all these years he still learned jackshit and only got a fake Super Saiyan 4 transformation he couldn't do again after Bulma's machine has been blown up

[Ki Breaker]

It's pretty widely accepted Vegeta lacks the creative sense to come up with ways to get stronger..
Vegeta might be a Saiyan Prince but goku is the rediscovered Super Saiyan after centuries of it's disappearance..

[Steven Bloodriver]

It is really Vegeta's own fault, he acts like a complete jerk for most of his existence, and pays for it by training too aggressively. Hindering his progress as a warrior and leaving himself to be the warm-up before Goku. While at the same time, he never wants to take a moment to learn from his mistakes and just wants to instead give the cold-shoulder to nearly everyone he meets.

[Amerigo]

Goku is the Leonardo Da Vinci, Michelangelo, Issac Newton, etc of fighting. His creativity and ingenuity is mind-boggling.

Just look at Future Gohan: All the potential in the world but it was never reached due to sub par training. Meanwhile, present Gohan at 11 years old managed to be ten times stronger than his future counterpart. Why? Because he was trained by Goku.

In terms of fighting Goku would have an IQ of 200+, Vegetables would have 120. No matter how hard the latter works or how many advantages he has (Gravity Chamber, Gym, Higher BP at birth, older, etc) Goku will always be ahead.

[TheMikado]

Vegeta himself said no amount of training would ever let him catch up to Goku.

[Lord Frieza]

Well before he trained with Whis, his resume seemed to be "Push myself until I'm either badly hurt or nearly die" Rinse and Repeat.

Regardless of what your head cannon may be, Zenkai stopped being a thing post Frieza. That means Vegeta no longer gets big benefits from pushing himself to hard. Because of that his body likely spends more time and energy patching him up afterwards then working towards improving his fitness.

Basically he pushed himself twice as hard but was really getting only half of Goku's results.

[lancerman]

I don't know if that's the best way to look at it. Let's take it one at a time.

1. Goku was a SSJ first and for longer than Vegeta. Goku had 3 years of training post SSJ. Vegeta gained SSJ during that 3 years of training. They both spent 1 year in the ROSAT. So naturally the stronger fighter going in ended up being the stronger fighter going out. Goku likely obtained the augmented forms much faster and decided on a new tactic when he realized the limitations earlier. This really all stems from Goku being way ahead of Vegeta when he traveled to Namek and abused Zenkai's to outpace everyone.

Conclusion: That's not bad training, it's Goku having a gap against Vegeta that evened itself out when you normalized conditions.

2. Goku trained in the Afterlife. Vegeta trained on Earth. Goku achieved SSJ3 in a more durable body and proved he really couldn't handle the form in a living body. He likely never attains the form if he isn't dead. It's a waste of time and too stressful. So an augmented Majin Vegeta in SSJ2 was roughly on par with a more durable dead Goku in SSJ2. With Goku having the added ability to one up him in SSJ3 thanks to other world training and an other world body that Vegeta didn't have access to.

Conclusion: That's not bad training, it's Goku having access to better tools and methods thanks to being dead than Vegeta did as a living person over 7 years.

3. They both learned SSJB. Goku learned Kaio Ken from a deity in the afterlife that Vegeta never met. No other characters in the series know that technique. Even the ones who also trained with Kaio Sama. Vegeta had no way to learn that.

Conclusion: Again, not a fault of Vegeta's training. He didn't have access to the guy who taught Goku the technique to improve upon SSJB.

All these instances are un normalized and don't account for other factors. The entire opinion could be explained away as Goku got two different after life trainings that Vegeta didn't and got essentially 8 years where in one instance he learned Kaio Ken from the only master who could teach it and in the other took advantage of an extra durable body to achieve a wildly inefficent level of SSJ. Then on top of that Goku got the benefit of a super cheese training in a high gravity spaceship where he abused Zenkai boosts like crazy, while Vegeta flew straight off to planet Namek and didn't, and it resulted in Goku outpacing Vegeta when they basically had similar training time from then on because a gap was already established. It's not bad training by Vegeta. It's more training and different training by Goku.

[ABED]

2. Goku trained in the Afterlife. Vegeta trained on Earth. Goku achieved SSJ3 in a more durable body and proved he really couldn't handle the form in a living body. He likely never attains the form if he isn't dead.

That's pure conjecture. He likely would've reached that form but would've discovered its drawbacks sooner had he not died. There's nothing in the story that implies reaching that form is a matter of either other world training or being dead. Vegeta is simply less creative than Goku. Even after he sees the fruits of Goku and Gohan training in the RoSaT, he doesn't emulate it because he's too insecure.

[Lord Beerus]

2. Goku trained in the Afterlife. Vegeta trained on Earth. Goku achieved SSJ3 in a more durable body and proved he really couldn't handle the form in a living body. He likely never attains the form if he isn't dead.

That's pure conjecture. He likely would've reached that form but would've discovered its drawbacks sooner had he not died. There's nothing in the story that implies reaching that form is a matter of either other world training or being dead. Vegeta is simply less creative than Goku. Even after he sees the fruits of Goku and Gohan training in the RoSaT, he doesn't emulate it because he's too insecure.

I'm not so sure. SSJ3 was really seen as a transformation that was not possible through any kind of conventional means and bit a fluke form to achieve, in all honesty. There was really nothing creative behind the process of SSJ3, as there was nothing creative behind the path to becoming SSJ2, because Goku and Vegeta both achieved the form during seven years of training. So what makes SSJ3 so special? I doubt Goku would have achieved SSJ3 if he were alive. Gotenks managed to become a SSJ3 by just powering up after training/fighting in the ROSAT for a few hours. Of course, you could hand wave that the kids are very powerful and fused together, pooling their strength enough to reach SSJ3 tier. But they are never taught by Goku on how he achieved SSJ3. All we know is that being dead means Goku can maintain SSJ3 for longer. It had no real bearing on the methods Goku used to attain the form in the first place.

[lancerman]

No normal living human has efficiently used SSJ3. Goten or was a fusion with a time limit pooling two SSJ's together. Goku was dead the only time he used it without pretty much being sapped of strength in one battle.

He also achieved it after 7 years of other world training and his other world body was the only one to truly maintain it. That's just a fact. There was no incentive for Vegeta who didn't know fusion and wouldn't use it and didn't have a body that was capable of handling SSJ3 to even bother with attempting anything like that form.

It's more conjecture to say Vegeta is less creative. He simply had different training and was behind Goku after Namek. When you normalize everything, there is nothing Goku and Vegeta did that was all that different.

[LightBing]

Let's break it down.

Namek Arc:
Not good for comparison, Vegeta didn't even train during the arc. Fighting and zenkais, that's it. Goku did gravity training and zenkais.

Android Arc:
Not only was Vegeta decently weaker than Goku, he also had to achieve Super Saiyan. Since creativity has been mentioned in the thread, I'll add that Vegeta also created the Big Bang Attack during this time. Goku was taught the Shunkan Idõ.

Clearly Vegeta's training was great during this time period. Piccolo is the only one comparable to him.

Cell Arc:
We have a question asked by the characters, can Super Saiyan be surpassed? Mr.Toriyama explicitly divides the Saiyans based on their growth and their answer. I exclude Gohan because he's a product of Goku and his own insane potential.

Goku clearly is ahead of Vegeta and Trunks. Goku chose the correct answer, mastering SSJ. Vegeta went for the middle ground, Trunks is the dum-dum of the trio.

In terms of not seeing the breakthrough like Goku did, there's no question Vegeta failed. Although it's necessary to point out that Vegeta trained alone, while Goku had great company.
Yes, Vegeta went in the first time with Trunks, unfortunately the Prince ignored his son. Which hurt both of them; training with a partner(s) is show to be massively advantageous compared to solitary training.

This to explain the massive gap in power, even after Vegeta went the second time into the RoSaT with knowledge of the mastering potential.

Shoot out to Piccolo, who got a massive power spike in his only trip to the RoSaT.

Boo Arc:
With the exception of SSJ3, Vegeta success is comparable to Goku taking into account their previous gap. Vegeta needed Babidi to basically cover the ground Vegeta lost to Goku at the Cell Games.

SSJ3 is a weird transformation and I don't want to get into it. Still just because of it we have to give Goku the advantage. That said, Vegeta's training during this time period was nothing but extremely successful.

I don't want to get into Super much and I'm only referring to the manga here, [spoiler]overall Vegeta is presented side by side with Goku. Only in the recent arc did Goku crawl ahead, with the 100% SSJB.[/spoiler]

All this to say that I strongly disagree with the OP. Vegeta training is mostly successful and I would put him together with Goku and Piccolo in the tier of smarter/better characters at improving/training.