True, but the problem you're mentioning is solved, for the most part. STUN/TURN servers serve this purpose, there are open source ones[0][1] and you can can even use public STUN servers[2] (as you might expect free TURN servers aren't really a thing).
Solutions like Jitsi Meet[3], whereby (formerly appear.in)[4] use WebRTC to great success and are fantastic for quick meetings.
WebRTC these days is pretty mature and ready for primetime -- TURN servers are a last resort, but they're a small price to pay for something that might be free (to you the service provider) most of the time, if signaling succeeds.
Solutions like Jitsi Meet[3], whereby (formerly appear.in)[4] use WebRTC to great success and are fantastic for quick meetings.
WebRTC these days is pretty mature and ready for primetime -- TURN servers are a last resort, but they're a small price to pay for something that might be free (to you the service provider) most of the time, if signaling succeeds.
[0]: https://github.com/jselbie/stunserver
[1]: https://github.com/enobufs/stun
[2]: https://gist.github.com/mondain/b0ec1cf5f60ae726202e
[3]: https://meet.jit.si
[4]: https://whereby.com