Sometimes you want to have a good game and have that excitement of completely crushing it.
I would vastly prefer if every match I play makes me at least _feel_ like I have a chance to win if I try hard enough, than have a large percentage be obvious losses leading only to frustration and waste of time.
Having some easier rounds also allowed me to goof off, like doing pistol or knife only rounds. Sure I didn't contribute as much to the team, but the team didn't need it and I had fun.
Having some more difficult rounds could make it more rewarding to win the next round.
But constantly having to play against similarly skilled players to me would totally not be what I'd be after.
SBMM with first party servers is definitely more accessible though. I'll grudgingly accept it if it means a larger playerbase and more active development for my favorite games.
The main complaint I've seen re: SBMM comes from top level players, including creators, who don't want to sweat / they want to beat players who aren't as good as them. To me this means SBMM is absolutely needed. Unranked play shouldn't mean better players can crush those who aren't as good.
This isn't even considering the fact that creators rely on looking good play-wise for their income, and SBMM makes this harder.