Nostr is pro-censorship
In Keys are meaningless we hopefully made it clear that keys are not central to Nostr's idea, in fact keys are just an unnecessary burden that enables something much more important: relays.
The fact that one user, through their client, can reach out to a huge number of these servers hosted anywhere, and that each user can publish their stuff to any of them, from a modest server at his basement to a big cloud relay hosted by a big company, without anyone having to trust any of these: this is the core of the Nostr idea.
And the fact that Nostr relies on an open ecosystem of privately-owned relay servers is the only thing that ensures a proper incentive structure and gives it a chance of working: while other centralized platforms and protocols in the past -- even those that have tried to be very open and anti-censorship -- ended up struggling against what whom or what should be allowed to be published or not -- because after all they relied on a big common "global" pool of messages that had to be interpreted by apps.
That reliance kills the entire idea because at the very least someone has to host the content, and hosting that content has a cost, it has moral implications and also legal implications, so at some point someone, somewhere, has to make a decision to stop hosting some things, or restricting some users from publishing and so on, and there will never be a global agreement between all the peoples of the Earth about whom or what should be allowed and what should be disallowed. Even a rate-limit, IP blocking or other naïve measures that a server must necessarily take in order to survive on the internet, are a form of "censorship".
On Nostr none of that is a factor because each relay is independent of each other and there is no global pool of content, by definition. Because of that, and because it's the job of the readers to figure out from where to read, no relay has any obligations to please all the peoples of the Earth and is free to impose any limits or policies it wants.
Of course all of that breaks down if apps relinquish their obligation to figure out what relays to read from and decide to read from a static list of relays, but that should have gone without saying.