[can16358p]

Especially given the fact that they could simply inspect bitrate in/out, they don't even need to access the actual video, it can be fully encrypted (even if not ATM) and by examining how much data is transferred they can know which quality they are streaming at.

[jtsiskin]

Except that bitrate is highly variable; a high quality stream of static content can use way less bandwidth than a lower quality stream encoding a lot of motion.

Now keep in mind they’re continually developing; perhaps testing different scaling preferences, or different codecs like AV1; suddenly you need a host of different bandwidth:estimated quality rates, that change over time and need to be kept in sync with client side changes… it’s not worth it