Why do you think WebRTC puts too much power in the hands of a few companies? It's completely open source and can do everything you want. You can take all the source code from either webrtc.org or chromium.org and use it to build your own end-to-end full encrypted communication system that no one can hack (as far as we know, and assuming you have secure device and OS).

The implementation at webrtc.org gives you cross-platform, cross-device source code in C++. You can build any API on top of that, in any language you want. It's already really easy to use if you an to use the HTML5 WebRTC API built into Chrome (and the same API in Firefox).

It seems to me that you have everything you want, or at least all the pieces of the puzzle. Someone just needs to do the work of assembling them the way you want them, and then of convincing the people with whom you want to talk (your friends, family, or business associates) to use your securely built communication system. Technology-wise it's possible, even fairly easy if you know what you want. But the social aspect (convincing others to use it) is more difficult.

(Full Disclosure: I work at Google, and I have worked both on Hangouts and WebRTC)