I use XMPP with bridging to IRC (to access freenode). There would have been no need to reinvent that particular wheel. Sadly the hype-train comment upthread also applies to Matrix.
Well, yes - the hype train is the whole point, as they were looking for something more popular than XMPP.
Though I would disagree with there being no need for reinvention - historically (and AFAIK unchanged) there are several real issues with XMPP [0]. The idea of XMPP appeals to me, but its complexity and UX are costly, whereas Matrix just works well and is easy to use, which hopefully will allow it to spread beyond tech circles.
Wasn't matrix (riot.im) hacked recently?
edit: found this https://www.reddit.com/r/privacy/comments/bca2k2/matrix_riot...
yes, the matrix.org homeserver was compromised. see https://matrix.org/blog/2019/05/08/post-mortem-and-remediati... for the details and what we did about it to prevent a repeat performance.
The protocol itself, the implementations, and the rest of the Matrix network was unaffected.
Have you looked into Matrix? It still has a few kinks to work out, but it seems to fit the bill, and the idea of bridging to other protocols (namely IRC and Slack) is an interesting idea for reducing friction.