Sounds interesting, I had to look up what SSO meant but I also think it’s not that big of a deal (I use ProtonPass for AutoFill + keeping track of my logins).

I guess almost everything is less bloated than Discord. I only still have that app for keeping in touch with former classmates, I seriously hate that UI.
If there’s a mobile app or PWA functionality, I might try out Zulip. There might be some overlap between the times where I am awake with some american “normal” time zones 🤔