No one relay can censor me. There isn't any central party, there isn't any special relay.

Client developers and relay operators are just random asses with a computer. Anyone can use as many relays as they like and whatever app lets them read what they want to (or develop their own).

This is in contrast with mainstream social media. If I go on Twitter and write "cisgender", Elon Musk can shadowban me. If I get on Nostr and say something any specific person you can name doesn't like, none of them, individually, can censor me.

Of course if the whole world agrees to censor me I will be censored.

Using Nostr doesn't make you depend on any specific computer owned by someone else, except those which we'd be using regardless of Nostr (DNS servers, ISPs and so on).

Fiatjaf cannot censor me as his own individual choice. The operator of any specific relay cannot censor me, because I don't depend on any specific relay and no relay plays a central role.