@Giacomo Zucco had a great talk on this in vegas in the context of bitcoin. You need to filter or else your system will be overrun by people trying to bring it down

A rose by any other name...censorship is censorship. Calling it "filtering" is silly...

The Bitcoin protocol is censorship resistant, but users can choose to use Coinbase which requires KYC and sets limits on transactions. The Nostr protocol is censorship resistant, but users can choose to interact with relays or clients which filter in a way which improves their experience.