80% of all observed ActivityPub accounts are on 30 servers, most of which do not block very much.
I have said this numerous times before, I really don't see the issue you speak of. Yes, some communities do a lot of blocking, and some of them do it very loudly.
The number of accounts this actually impacts is pretty negligible.
And even if it wasn't, they too do it for the very same reason you agree with - abuse - they just have a different definition of abuse than you do.