The killer feature of discord was always "open this link for our guild voice and let's go into the dungeon". And this is a brand advantage: you can try that with self hosted tools but discord "feels safe" to click.

The only thing TeamSpeak has on it is multi level voice for complex command chains. But you pay for that with enormous sign up friction.

There's no viable frictionless chat alternative. Maybe jitsi. And if you try to make one? You'll get regulated and have to do the same thing.