That could become a problem, however most clients are opensource and I am sure if this problem gets too large you would have people hosting their own client instances without any of the things you mentioned. I definitely don't think it's a deal breaker which makes NOSTR protocol completely useless.
Discussion
I didn't say it's useless. Just that it's not better than fedi that has been here for longer came trough fire and you know what to expect there. It's solid.
Yes people are already and will be hosting their own client. That most are opensource is meaningless here. You are talking about miniscule percantage of people same is valid for fedi. This is not what most users will do, for same reason most users stay on heavily censored instances like mastodont.socialists or stayed on censored Twitter for 3 years - they are liberals it's in their nature that they OBEY degenerate majority and popular opinion, they are incapable ot thinking, and thus censor themselves by their own idiocy. Target of censorship is always this stupid majority weaponized as a rabid herd of bullies to supress minority they are not victims. They are collaborators. It's mental illness. The protocol is completely useless as a solution to censorship.