Fluxer keeps coming up as a Discord alternative. It looks good, but it has one major problem: It's AGPL and it requires a CLA.
That is an enshittification time bomb. I personally will not contribute to projects using that combination, it's gone wrong way too many times.
That's not to say it's bad to use as a hosted service, it being open source at all is better than Discord.
But from an open source point of view, it's not a good licensing setup. It basically creates a system where the project owners have more rights than other contributors. It's not fair.
Edit: For ref, this is the formal CLA:
https://cla-assistant.io/fluxerapp/fluxer
TL;DR "We can do whatever we want with your code, and license it under any license".
