Since it’s related, here’s a good comparison:

https://eylenburg.github.io/im_comparison.htm

I think the other person here explained the thing about user ids. Matrix and xmpp are good too, they’re just different.

Simplex is more of a messenger, while xmpp/matrix are more of discord alternatives.

Also simplex works with nodes. I can host a simplex server and it will be added to the network. In matrix/xmpp if I host a server it will be a new instance, like in lemmy (if I get it right). Simplex’s approach is like tor’s approach, each server added contributes to the whole network (they arent a separate instance).

If you check their page they have some bery good features, to me it seems like its signal, done (somewhat) right. Signal doesnt even have a proper way to migrate accounts across devices… not to mention the phone number requirement which might scare people who aren’t gonna waste time hearing my explanation as to why it’s not an issue or the fact that until recently signal would notify everyone in your contacts who had a signal account that you made an account, bruh

There’s also this comment here that throws some shade to matrix, havent looked much into that tho.