There are dozens of clients already. Hopefully, we get to thousands. You don't need to create one from scratch, you can just fork it and remove the things you don't like... like Onyx did. Clients make 100s of decisions in the visibility of posts. For instance, Amethyst didn't show non-like reactions until this week. They were always displayed as red hearts. Is that censorship? To some extent, yes. But if so, then every client is censoring everyone, all the time. Don't trust anyone. Not relays, not clients. The only thing you can be sure of is the code that you can see and verify. If you can't verify, hire somebody who can, or fund a group that does it for you (but then you are trusting the group).