Nostr solves for public speech.
We still need a good option for decentralised private messaging.
Matrix?
SimpleX?
It must be FOSS. It's the only way to check for back doors.
Discussion
What do you think about NIP-17? If tor connections to relays are used it looks like it does a good job of obscuring event meta data. I don't know what clients use it yet but the rust-nostr crate supports it.
It looks good, but I need to learn more.
I'll read!
I had a bad time attempting to run a matrix server and I've observed people in charge of matrix servers complaining that the protocol is extremely bloated. it's definitely not my first choice