The thing to understand about this defederation drama is that the federated system don't
create these stresses, they
expose them in a visible manner.
Reddit has all these problems too, as well as any other big site like Facebook, etc. The solution there is a one-size-fits-all policy that generally, surprise surprise, conforms whatever the dominant culture of the company that created it is. I mean, what else would it be, right? No sarcasm. Then further modulated by the commercial interests created by the advertising-funded nature of the large-scale community. And especially because of that, the desire is typically to just shovel any conflicts under the carpet.
But these pressures are still there. They often seem to explode at some point. Reddit may or may not be seeing that now.
This is why I remain unsure and unconvinced that these one-size-fits-all communities can function as communities for the long haul. There's this intrinsic build up of stresses that will eventually overwhelm the system. Clearly they can function for a decade or two, since they have, but can they go beyond that? Yeah, in Internet time that may seem like forever, but it really isn't all that long or stable on human time scales.
You simply can not shovel the whole of humanity into one "community" and expect it to work.