The series should have ended after Cell with the torch being passed to Gohan like it was being built up to since the beginning of Z and the future lives of the characters being left ambiguous.
Instead it reverted to Goku fanwank and Mystic Gohan being a joke of an existence
Honestly, and I'm probably in the minority with this, the Android/Cell saga turning into a Gohan story at the very end always bugged the shit out of me, mostly because Gohan spends almost the entire arc as a background character. And by the Cell saga I was sick of Gohan being a deus ex machina. The one thing I appreciate with the Buu Saga was how Gohan took a few steps backwards after Cell. Considering Gohan was never had the fighter mentality of Goku, Vegeta, or Piccolo and was more or less drafted into fighting it made sense that his priorities would shift in a time of peace. Plus Buu Saga Gohan is the only Gohan who actually develops a personality.