I remember Verita I think said that once Nostr users have to deal with stuff they don't like, they are going to implement pretty strong censorship and isolation, just like with the fediverse. If someone doesn't have the most vanilla beliefs then their notes will be rejected by the majority of relays. For an extreme compatison, take a look at the "pediverse", a collection of ActivityPub instances with a whole bunch of pedophilia posts. If the only place where your notes aren't ignored by relays is a small archipeligo of relays then how is Nostr any different from ActivityPub or Mastadon?

That's the prediction and criticism as I remember it. I think the prediction makes a lot of sense. Everyone has a different idea of what speech and free speech are, and I expect that the people involved with Nostr won't see any issue with cutting out any notes that don't meet those subjective standards.

Where I differ from Verita is in the idea that this outcome wouldn't be meaningfully different from ActivityPub's circumstances. For me, I used to have a niche community of outcasts whom I may not have trusted to accept me, but whom I at least trusted to insult me to my face. And then I lost the ability to post to that community, with not so much as a warning or a "you've been banned" message. To this day, none of the users have a clue that something even happened.

When I look around on the fediverse and the rest of the internet, I see plenty of other platforms that I can see myself trusting and that I think would allow me to post freely. However, I know that no matter what, I will never feel right posting on a platform like that. If I continued posting on sites where third parties can wield absolute control over the ability for two users on the platform to interact, I would get a nasty feeling in my gut. It doesn't matter how much I trust the site and it's administration because I need to go by a different standard now.