Earlier quoted context omitted.
Surprises me too. For decades, we had incremental improvements where more and more privacy and encryption was added to chat apps (e.g.: WhatsApp used to send messages in plain text, then added encryption to the server, then end to end encryption), and then Discord came along with none of that and all the gamers felt a need to use it. Eh? I was a gamer until just before Discord appeared but what ever happened to thing…
Discord's killer feature is the voice channels. The ability to join/leave the call easily is great. You don't have to ping people to get them into the call. You just hop in, and people can filter in/out as they please. It's very convenient.
That's precisely how Mumble works. People just don't know it anymore, open source application with no profit model, doomed to fail in favor of, or competition with, commercial services I suppose...