If you're thinking about making a new instance, keep in mind that there are plenty of instances full of alt-right sadboys. But here, you can do something about them by blocking those instances from yours.
I have a list that I keep regularly updated, and it documents a lot of examples of the kinds of things people and admins say on an instance, and I deconstruct common bigoted dogwhistles and conspiracy theories!
[NO LONGER UPDATED] A detailed and extensive blocklist advisory for ActivityPub instances (ie. Mastodon, Pleroma, GNUSocial, etc.). - dzuk-mutant/blockchain