Mumble does that one thing just fine, but it doesn’t do all the things discord does.

And it’s not just the fact that discord does all those things that’s made it so dominant; it’s the fact that it does all those things in one place.

Even just the core features of voice chat, text chat, and the ability to set up a new server where you have extensive moderation control in one click – it’s what people wanted.

They don’t need a handful of different programs to glue together a shittier experience, they need a FOSS discord/slack.