A client developer or relay can prevent you from seeing certain things (and should, actually). But they can't force every other client and relay to do the same thing. That's my point. I want clients and relays to hide certain things from me. I don't want to see child porn or things like that. I saw an AI generated child porn image in a client I used to use. I don't want to associate with relays or clients that don't try to filter stuff like that. The idea that zero filtration is good is simply nonsense and I wouldn't use Nostr if there was no way to shield myself from stuff I don't want to see. But I have options if I think filtration goes too far (like filtering a specific political party, etc)