I've cut out half my lemmy use because of the political extremism on here from Hexbear and Lemmygrad. Lemmy.ml isn't all that much better. I'm not the only one drifting away because of it.
Hang in there. I've heard word that soon users will have the ability to block entire instances. Personally, I've just blocked every Hexbear account on sight, and it seems to be improving my experience. I've also started to unsub from .ml communities, since I've noticed the same things you have.
I think it will make a huge difference. Personally, I never understand why defederation is frowned upon. There are some instances that are just so toxic that they don't deserve to be heard.
For the record, I'm a bit of a political extremist myself being an anarchist, but the users that I dislike are people who dunk on you without even giving you a chance, and political opinions that excuse things like authoritarianism and genocide. There's a lot of that on hexbear, lemmygrad, and even .ml