I’m also more of an irc person. I’m in the middle of a chat upgrade at work which may well go matrix, but even then, I’m building (using matterbridge) bridges so that xmpp and irc can interact with, well, whatever we implement (at the moment i can go to several rooms on xmpp<->mattermost<->matrix).
There are also a LOT of other forums on irc that are simply not matrix…