I find it ironic on a free speech platform that access to a community about censorship is censored https://exploding-heads.com/c/censorship
What exactly is wrong with this instance to be defederated? In browsing it, I see nothing hateful
Or did they defederate from this instance, so you cant view/post on it. Not sure if I completely understand how that works yet
An environment where anyone can spin up an instance where they control member accounts and then post on other instances with impunity would obviously be an unusable hellscape of griefing and abuse. The only, ONLY, ONLY way a community can survive in these conditions is if they have power to censor the content that they syndicate. Indeed, that is the whole point of community groups vs just consuming raw Internet; the content has been curated (aka censored) according to some set of rules.
There are pure P2P networks that function the way you want. Go take a look and discover why no one is there.