It's a matter of numbers and community.

If you want to be a jerk, people will ignore you. If there are ten other people in the room, you can only be a jerk ten times before everyone in the room starts to ignore you.

That's the Fediverse, it's a small community and word gets around fast with people who see and notice a bad character and start blocking them, their posts, their comments and their activity.

That's the thing about numbers .... if you are a small group, word gets around quickly who the jerk is ... if you are a big community, there are more systems in place to deal with jerks

So the only way for jerks to survive ... is to build a community of jerks for themselves ... and surprisingly enough, those communities don't last very long.