I think mastodons approach is a very good approach. You can as a user block entire instances.
And if you are on a good instance many abusive instances are already blocked.
So everybody can have their little space without shitty people.
Especially because city people tend to accumulate in certain instances since they’re not welcomed on eg. mastodon.social
Unfortunately, a lot of instances that block have a double standard where they won't allow nazis but allow anarchism and communism, and all the other ideologies, with people openly promoting harassment towards others. I have not seen an instance that blocks both yet.
You can always create your own with like minded ppl.
Maybe some non political instances are a shot worth.
The problem there is that everybody has its own definition of “extreme left” and “extreme right”.
So it could be that your preferences are just a bit niche or something like that :)
So everybody can have their little space without shitty people.
Especially because city people tend to accumulate in certain instances since they’re not welcomed on eg. mastodon.social