For the moment, youtube-dl works, but it is not ux friendly if you want to browse unknown or related videos instead of downloading a specific one / list.
I agree with the fear that the ocurrence of sponsored content, "educational ads", in-video placement and all those sneakier versions of ads, that you sometimes don't even notice, will grow a lot in the near future.
Both of which[1] got me to install an ad blocker and back that up with a pihole at home. There'll always be a way past ads, or an alternative to the site they're on. It's a big internet
[1] Actually it was more the ad volume that did it. I'm alright with ads if they're not ridiculously frequent but when they're twice as loud as the video I'm watching I'm gonna get rid of them