Think about it; instead of those in charge or the instances deciding who they don’t want to be federated with and thus restricting content for the users, it would be better if users were able to block entire instances instead.
We’d be able to curate our own browsing experience so much better without admin/mod drama influencing the rest of us.
Edit: Alright so maybe not exactly replace defederation, but it should still be an option available to us, and in general should become the default action before defederation IMHO.
When it comes to instances that are unmoderated and full of spam or oriented towards questionable porn, it’s a better idea to defederate. Lemmy admins could face legal jeopardy for CSAM, spam bullshit can be a security risk. No reason at all to help host or spread that. As far as trolls/politics, I think it’s reasonable for instance admins to decide whether they want to amplify and serve people say, some hateful content about hating minorities or accusing people of being “groomers” or whatever bullshit. If I ran an instance I’d have those people off my site pretty quickly. As far as instances that are just sort of provocative or have questionable political views, sure. Instance blocking (which is in the works, I believe) would take some pressure off the admins to defederate entirely.