As far as I understand it, lemmy is a hub for anything and everything anyone wants it to be.
You can block instances, communities, and accounts to resolve the problem as you see it if you wish, but in my opinion the real move is to learn to be able to read anything and everything in order to obtain the widest view possible without allowing it to affect you personally.
I feel that if people learned to respond honestly and rationally without logic fallacies and worrying about things as paltry as votes, then we would be better off ultimately.
That's not to say that it is easy - but I firmly believe it would be beneficial, specifically because I think it would cut down on echo-chamber effects.