[quaffapint]

Yes, you can try it as a Premium member. I didn't try it on any 3-hour long videos, but for a couple of shorter ones it worked well enough to give a tl;dr;.

[Tostino]

Hmm, it's not showing up for me to try in my account...

Here is the site talking about the features though: https://blog.youtube/news-and-events/new-youtube-premium-fea...