[pacija]

It's apples vs oranges. I selfhost and use both, ejabberd / conversations for xmpp and synapse / element for matrix.

XMPP is traditional IM. I use it exclusively from Conversations client on Android / GrapheneOS and it is really instant, supports presence (knowing whether contact is actually online), rings for audio and video calls, gives feedback about whether user read the message etc. I use it mostly for 1:1 conversations, it has all but replaced SMS and phonecalls.

I consider matrix more like 'fast forum'. Perhaps things changed but last I checked (from element on Android / GrapheneOS) there was no presence so I have no idea whether contact will get my message immediately or not. No confirmation that contact read the message. Audio and video calls not working, not even ringing when phone is locked. Quite laggy in message delivery.

So, after some years of using both, XMPP is best for replacing one-to-one SMS, video and audio calls, while I enjoy hanging in public matrix rooms, treating them like '(not really) instant forums'.

[gtirloni]

Matrix has presence but not all public servers enable it.

https://spec.matrix.org/v1.11/client-server-api/#presence