Why didn't Toei change the video for "WE GOTTA POWER"?

[Fantastische Hure]

And the ending for that matter?

The entire opening and ending are focused completely on Gohan. It's as if to say now DragonBall is the Gohan show. Obviously seemed like it at the time but then once Gohan got defeated by Boo I think that went-out of the window and Gohan stopped being the main-character.

It seems like Toei liked the idea of Goku being the best, yet they didn't change that.

Interesting

 

[Captain Cadaver]

Changing the OP animation whilst retaining the song would cost a little bit extra in producing the animation to use in each episode, which I doubt someone as cheap as Toei would want to do at the same time their studios were also busy milking Sailor Moon.

Along with that, the changes made for Cha-La-Head-Cha-La over its run were pretty minimal in matching the current series, with the Cell Arc version still utilising Saiyan Arc Gohan and Goku throughout most of its run. In terms of in-series changes, the Boo Arc had far less to make an updated OP/ED animation necessary, especially when the possibility of Gohan or the kids becoming the new hero remained open until very late into the arc.