On AP, because identities are tied to instances, the instance admin can kick the bigot and they’re gone for everyone, before many folk ever see it. And if there is an instance with admins that don’t deal with bigots, the admins can defederate from the entire instance.
Same with Nostr. Relay admins can ban users and relays who don’t have good moderation. The difference is, if you don’t agree with that ban, as a user you can: connect to other relays and route around it (so you can still follow/be followed by/DM your person/relay of choice) AND keep using that original relay because you like the content on it (if they banned another user, not if they banned you). And there’s no need to make a whole new account at another instance, login to it separately, etc.
In Nostr, your relay gets to make and enforce it’s own content policies just as easily as it does on AP. They are literally the same in this regard.