I didn’t mean like they just strait up embed video.mp4 on page for the video, but as far as I understand on their backend they still have actually video files of various resolutions and such that they serve to you.
Even if the page isn’t giving you a copy of a strait up file in the way it might in 2000, the player is still pulling a copy of a pre processed video file stored on YT’s servers, and in order to have the ads as part of that same file in order to make adblock very hard to implement they’d need to re-process it any time they want to show an ad that hadn’t been already inserted into the video.
I could be completely wrong tho, I don’t work at YouTube and haven’t built a video sharing site before.
Thanks for the breakdown and the link, cool to learn about the new (well new to me) tech, sad to see it’s gonna probably bit us in the butt at somepoint.