I’m not 100% sure but I think you essentially described how Nostr works in your first paragraph.

Does Nostr have many users these days?

Noster is cool, I've experimented with it but it doesn't solve all of my problems and has some problems of its own, such as spam. Most importantly, it's not really P2P, despite being decentralized.

I have also explored other P2P approaches and built prototype social networks. I prefer a more P2P approach, I think it's more scalable, but it's complicated because IP privacy by default is important in large social networks. I'm still searching for the right solution. I think the advances in LLMs are going to help do a much better job at solving the moderation problem in social networks, and so I am experimenting with that in my off time.