In every Saga every other Z fighter made some kind of contribution.
SSJ Saga Krillin hit Vegeta with the spirit bomb and Gohan helped out and even Jajarobi cut of Vegetal tail. Yamcha died but at least everyone else fought.
Frieza Saga Vegeta did damage and even Piccolo held his own against Friezas second form. That was probably the most Goku focused time out of all the Sagas.
Cell Saga had multiple instances where every character became powerful and was able to hold there own against a villain at the time. First Vegeta beating Android 19 after becoming super saiyan. The Piccolo fusing with Kami and beating android 17. Then trunks and Vegeta being able to beat Cell's second form. And of course Gohan SSJ2 finishing it off.
Buu Saga had Gohan be the main protagonist for most of the time until Goku got brought back to life. Even then Trunk and Goten became Gotenks and were able to match Super Buu at the time. Had their fight with the main villain. Then Gohan achieved Mystic form and becmae the strongest non fused fighter of DBZ. Then Goku and Vegeta came back and became Vegito. Finally ending it with the classic Spirit bomb.
What I'm saying is that at least in the past the other characters even the fodder were useful in even fighting the main villain at certain points. Now all they do is cheer on Goku and Vegeta. The other fighters really have no reason to even be there. Now its more Goku focused than ever. Btw vegeta should have killed Frieza not Goku in the movie.
