Did Z, Super and GT need to exist?

[KBABZ]

The Vegeta fight in the Buu saga ultimately boils down to formalities on Goku's part because he's so much more powerful by that point; as Vegeta learns later, Goku had SS3 up his sleeve that whole time, so he really just did the fight at Vegeta's insistence more than anything else. The original Saiyan fight had a lot more on the line for both combatants and there was no shying away from the fight itself happening, which is not the same with the Buu fight in my opinion.

[ABED]

How was there more at stake in the first fight?

[KBABZ]

Well Vegeta was looking for the Dragon Balls to wish for eternal life, and eventually threatened to exterminate everyone on the planet. In the Buu fight it's just to fight Goku and prove that he's better than him. Yeah he killed half a stand's worth of people but to me that was mainly to force Goku to fight him.

[ABED]

Well Vegeta was looking for the Dragon Balls to wish for eternal life, and eventually threatened to exterminate everyone on the planet. In the Buu fight it's just to fight Goku and prove that he's better than him. Yeah he killed half a stand's worth of people but to me that was mainly to force Goku to fight him.

If Goku takes enough damage, Buu would be revived. As we saw, that's exactly what happened and not only did Buu destroy Earth, he destroyed other planets and threatened the existence of the entire universe.