It’s a federation of servers with individual communities, so if a server/community is toxic stop participating in it and find or start an alternative. But most communities are tiny to small.

Edit: spelling

Checking your comments you seem to have had a run-in with the ML-crowd. Lemmy generally has a plethora of “leftist” (if you restrict your political compass to one dimension) communities, although the variety is immense. Let’s just say there is some … unfriendly turf here on the Fediverse. Plenty of people on the German communities avoid .ml communities.

I consider it to be the price of diversity. Due to the lack of central moderation (except on authoritarianism-loving instances), communities are much more self-regulating. On better (aka not US-politics) communities people tend to simply disagree or discuss, but rarely go beyond that.