I admit that the never ending algorithm of YouTube is problematic, but your point about kids fixating on things highlights it is nothing new. When I was a kid it was TV and video games. We had rules about when both could be used, and they were often taken away as punishments.

As we got older, my siblings and I had full on fights over who got the use the phone and when.

My point is YT is just another thing parents need to manage.