If they did that then they’d have to re-encode videos for each veiwer (which would require an insane amount of processing power), or give up on tracking and have contextual only ads.
Their only real option is to have ads as separate files and then use the magic JavaScript to tell your computer to play one file then the next, which is where adblock comes in like “naw, let’s not do that”.
Debian or Alpine would be perfect. Debian has bigger repos, better hardware compatibility, and maybe a bit more stability. Alpine is scary lightweight and a small ISO download.