Personally, while I am forced to use Discord for work, for participating in open source communities or any other sort of interest-based community, I will only use IRC.

It's not even solely the spyware and proprietary aspect of it, though that counts for a lot. It's also the fact that I can use any IRC client I desire and I am not forced to use either an Electron app, or a web browser tab. Also the quality of people seems to be significantly higher. But hey, at least Discord is not Slack! That I really won't use, due to the fact that I have to install the Electron app.

Matrix is extremely unreliable so I gave up on it a long time ago.