If you tie it to a Google account you can tune them by watching videos on topics you are interested in, as well as flagging videos & channels with "Not Interested". Their algorithms are definitely eager to find you a flood of content you'll enjoy. The hard part is seeding it with high quality channels.
IMO it's too eager. I watch 1 video of dashcam crashes, and my recommendations get polluted with them. Same with 1 video of tennis. The algorithm seems designed to keep eyeballs in the app. This lead me to switch to NewPipe on Android, where the "front page" of the app is customizable, so I just leave it to "most popular videos in $country", they all happen to be music videos and not have click-baity titles.
My best guess is it's designed to recommend the higher ad paying videos, I can only imagine dash cam videos are extremely monetized. I would wager it's not about keeping you watching, but keeping you profitable, it's not their fault the people uploading exploit what people will watch for hours, just their benefit.
I think this is a recent change (over the past couple of years?) in their algorithm.
Every now and then I will watch a video which will cause my recommendations to be flooded with nothing but stuff like that video, and videos from series that I have been watching regularly for years get buried.
