Zamasu and Goku Black tho do make up for it a bit by being real cool characters.
100% agreed on this. Zamasu especially was hugely entertaining for me, and the sense of mystery surrounding him and Black for a stretch was really cool and unique. Easily the best part of the arc outside of the roller coaster of a final stretch was seeing his motivations develop in the present while everyone else was trying to work out how things got the way they were in the future.
Literally all of this happening because Goku's a moron and can't resist sparring with strong people is kind of incredible and I actually wish they explored that a bit more.
To be fair, if Zamasu were a normal Kai there'd be no reason it couldn't be a friendly spar, I didn't see that as moronic by Goku. He had no way of knowing Zamasu would spiral out of control like that. Also it actually proved instrumental in confirming beerus's and whis's suspicions about him, since if Zamasu wasn't fighting they wouldn't have been able to feel his ki be similar to Goku Black's. ---