The problem is defederation. It basically breaks the entire concept of the “fediverse” and will prevent critical mass. Each instance becomes a little fiefdom. There should instead be the ablility to create and share extremely configurable filters (ala ad block lists). People can say and do whatever whilst simultaneously choosing what they do and don’t want to see at the individual level. The benefit is everyone sees what they want while also not losing access to any communities simply due to an egotripping instance provider. Kind of like an urbit model that isn’t so esoteric and weird.