I recently implemented a WebRTC multiplayer game in Godot, and yeah, it has very little to do with chat, and isn't really "off the shelf", it took a hell of a lot of configuration, plus running and maintaining a STUN/TURN server and backend lobby/matchmaking system. It's no more a chat protocol than HTTP really when you're doing that kind of programming with it, just has some nifty tricks for getting around routers and making a direct connection where it can.

That said, it was better than NAT punch-through and/or UPNP which are not very reliable these days.