In the last two weeks youtube started having problems with uBlock. If it's on, youtube refuses to play videos that have ads on. At least for me. Maybe they are testing the ad-block-blockers, and I'm one of the subjects.

any videos in particular not having any issues myself

youtube-dl already violates the ToS, of pretty much any service it supports. But I doubt it'll ever make up a noticeable amount of traffic and it's certainly very useful, so my personal bet is tools like this will mostly continue to work unless they somehow become a threat to services in some way.