I also REALLY hate how both of them want servers to expose the lists of users' connected clients to the outside world. Matrix does it supposedly for e2e encryption. XMPP does it for no good reason.
@grishka Modern XMPP clients also expose it for the OMEMO devicelist (e2ee).
Gregory's Server
@grishka Modern XMPP clients also expose it for the OMEMO devicelist (e2ee).