I'm fine with how Buu saga turned out. If he fused with Goku, they'd have been -way- too strong, and without a doubt would've killed Buu then and there and stay fused (disregarding terrible retcon in Super).
Goku's Spirit Bomb was also a much better finish for Buu. If Gohan was there he would've defeated Kid Buu on his own.
Throughout the entirety of Super, Gohan has been climbing back to reclaim his power. It's been good development. He jobbed against Freeza terribly and since then has started training. He got -really- serious with the ToP because he realized he needs to be a fighter, he can't rely on his father because Goku is literally what caused the ToP.
The ToP would have been an amazing climax for Gohan to have gotten a new form (as he declared) and win. It's a shame, but I do hope that happens in the future.