Check out: - https://appear.in/ - https://talky.io/ - https://screenhero.com/ - https://github.com/feross/webtorrent - https://peercdn.com/ - https://sharefest.me/ - ...and lots, lots more. Sorry to the ones I forgot to mention/don't know about.
For some pure WebRTC experiences. http://simplewebrtc.com/ if you want to build something yourself.
The thing is, you don't know that the service you're using uses WebRTC, quite frankly because the technology doesn't matter, the user experience does. Also, the sheer fact that we seem to have standardised a very good (and very secure) way of doing peer to peer transfers, and that's getting implemented in browsers, with client libraries for iOS and Android is HUGE.
I think the biggest problem is the lack of accounts, chat, logging, and persistence in webrtc. Thats what keeps it from being a p2p communication protocol in general whereas now its just a toy for video calls.
I mean, when you cannot share links during your video call easily, somethings wrong.
Sharing links, accounts, chat, logging and persistence are all irrelevant for my use, and they in any case don't belong in webrtc - webrtc is a component for people to use to build services like what you appear to want.
WebRTC is not a messaging technology, it is a raw data communication technology. It is just here to move bytes from one client to another. The features you are talking about are managed by said clients, meaning that it has to be handled by Firefox/Chrome itself.
Of course, with it being added generically, tons of websites immediately started using it..... nope. Ok, well, lets go back before that blog post... https://hacks.mozilla.org/2013/02/hello-chrome-its-firefox-c...
Ah ha, isn't that neat. WebRTC in Firefox and Chrome and a demo of it! Wait, still pretty much zero use in the wild of WebRTC...
This is why Google/Mozilla are adding features utilizing these new specs to the browser, because they're cool and no one else is. In the case of WebRTC, it's for a good reason, its a PITA to run TURN/STUN servers to ensure that people behind firewalls can establish a connection.