I use watch later for completing videos, but these are just I think may be interesting from the homepage, like seeing the title and background pic. I sometimes open multiple tabs for them.

One of things I found the coolest, was when I am watching a video, and if the video mentions for example some event that happened a while ago or a person being referenced, I would immediately search for that, and I would see it already recommended on the search bar.

Maybe lots of others have also done the same, and it recorded that as a meaningful suggestion. Or maybe it's standard ML techniques, or the new Transformer models diffused across Googles products I'm not sure but was noticing this even around 3 years ago.

I wish though it would surface videos in my watch later in the recommendations page. As it is "watch later" is where videos go to get forgotten about.