I am a firm believer that there are many privacy techniques you should focus on before encrypted messaging because they will offer you much more “bang for your buck,” things like good passwords, two-factor authentication, and even encrypted email. That said, I still believe that encrypted messaging is a critical part of a well-rounded privacy and security strategy. While the vast majority of our day-to-day conversations may be benign, it can still offer a lot of insight into who we are as people – our routines, likes, and personal thoughts. This information – mundane or not – is worth protecting.
It isn’t easy to setup and the core protocol is dated. You can add all sorts of extensions but at the end of the day the core system is old. It feels weird to push it over Matrix. If you want something simple use IRC as you can setup encryption.
Encryption support in IRC clients is WAY behind XMPP. The one I have seen consistently is OTR in form of an add-on, and even that people rarely install. Although IRC is indeed what I prefer for public groupchats.
Matrix seems to be doing the same thing but consumes more resources. And as for setup - I have done that, it is indeed pretty easy, easier than Matrix.