This is a really stupid oversight.. Twitch did subscriptions first and there they do disable ads on the channel you subscribe to (if it has them).
My touchstone for excessive advertising is a Polish TV station called Polsat, which often had very good programming but also lots and lots of ads. We often joked that Polsat programming was "all ads, sometimes broken up by a few minutes of actual TV". It wasn't quite that bad, but it was true that you would get just under ~10 minutes of adverts per every 15-25 minutes of programming.
YouTube exceeds that ratio, these days. And when that happens, I'm almost positive it's time to start packing your toys and looking for a different source of entertainment.
No one's forcing YouTube to send me the videos either. If it gives me ads, they will be deleted before they even make it to my screen. If they don't like that, they are free to return 402 Payment Required instead of giving me stuff for free.