[ezst]

> Matrix supports encryption out-of-the-box

that's not true for most clients, though (AFAICT, only riot works with itself).

I might even say that the situation is better/more sustainable in XMPP where more diverse implementations of the encryption protocol are available, with all mainstream clients supporting it: https://omemo.top/

[kitkat_new]

FluffyChat and Syphon are doing pretty well. I don't think any of the clients are mainstream

Riot doesn't exist anymore. It's been Element for a while now