If I understand it correctly, this is what tor browser does, in addition to using the tor network itself to as-close-to-anonymize you. Tor browser has warnings that encourage you to not-resize your browser because that could be used as fingerprinting data.
Well, I was thinking about enabling those on specific domains only (leveraging the container feature).
An interesting (research) approach would be to taint the data that can be used as fingerprinting, and forbid its exfiltration, perhaps with different levels of aggressiveness.
Example: a webGL game requires my wwindow width, GPU capabilities, etc? fine. But now, the thread that has this data cannot send anything to the other threads.
It would require some adjustments, and tightening the side-channels (making available download bandwidth/timings/etc more granular, for once). I do not expect it to be completely fingerprinting-resistant, but it would go a long way.
