Browser functionality needs a hard segmentation into disparate categories like "pages" and "apps". For example, Pages that you're merely intending to view don't need WebRTC (or really any sort of network access beyond the originating site, and even this is questionable). And you'd only give something App functionality if it was from a trustable source and the intent was to use it as general software. This would go a long way to solving the other fingerprinting security vulnerabilities, because Pages don't need to be using functionality like Canvas, USB, etc.