The problem with fedi is that you need some kind of lowest common denominator gatekeeper. So that a client can tell the server: I don’t want to see x,y,z and it works reliably.
In order to have that functionality, someone has to class that content first. You can’t trust the author implicitly, so you have to trust either the server or a moderation group.
How you define the mod group, be it random community member based on comment and post karma, or a trusted ring of insiders with votes, or some other method, data still needs a place to be stored.