I use thunderbird for email and they now let you connect to matrix, irc, xmpp, and whatever Odnoklassniki is. It's quite barebones however, like it looks like people are just adding lines to a google doc, barely any interface at all. Really a stylesheet would go along way, looks like userChrome.css works, so maybe I'll mess with that.
I tried Thunderbird for Matrix but I found it too spartan to be usable as my day-to-day messenger, unfortunately. I think most people are less demanding of their applications than I am, because Element, NeoChat, and Fluffychat are quite popular.
