I wish XMPP had stuck around. I used to run a Prosody server and it worked well enough but I think the E2E keys would occasionally need to be fixed. I used Conversations on Android as a client at the time. The things that makes me hesitate to dedicate too much effort to Matrix are:

1. the supposed funding issues they're having (which is part of why I paid for hosting)
2. the FOSS' communities seeming tendency to keep jumping messaging platforms and so there's never a chance for one to gain critical mass
3. how buggy the web client and Element iOS client have been.

When I stopped running an XMPP server I switched the only other user over to Signal and we've stuck there since. With how buggy the Element iOS client, Fluffy Chat and web client have been for me (app crashes when joining rooms, rooms don't exist when they in fact do), I don't want to risk an upset by trying to push people there since Signal is good enough. And these are all issues that exist when the company who makes Matrix (plus contributors of course) are the ones running the server.

At this point I'm just inclined to grab the export they provide and switch to matrix.org for the 1 or 2 rooms I care to have a presence in.