[LinuxBender]

I replaced Discord with Mumble [0][1] / Murmur. (Self hosted). It scales really well. On a tiny VM I could handle thousands of people. That said, it isn't quite as happy-clicky-frictionless as Discord. They are working on that aspect of it.

[0] - https://github.com/mumble-voip/mumble

[1] - https://wiki.mumble.info/wiki/Main_Page