Youtube is wasting ressources, it’s a fight they can’t win

nah, if they embed the ad into the video stream (they were testing this for some users!), the only adblocking option will be to blank out the screen and wait through the ad (or download the video in advance and edit the ad out automatically), both of which would make it a lot more annoying to adblock than currently.

YouTube Revanced already has a blocker for sponsor segments embedded in the video.

you can skip through sponsor segments, but these are ads from youtube, not from the creator, and youtube will not let you conveniently skip through the ads. if implemented correctly, youtube could ensure that the ad is fully played, which would need downloading and automatic editing to counter.

How would they determine if the ad is played without trusting the client? I guess they could screw with the buffer, but that would really piss of people with poor internet, and most people would prefer an ad-length black screen to whatever attention wrenching dark pattern manipulative brown noise wants to infect your mind today.