There are so many bad kid's videos on YouTube, and I'm not even talking about the algorithmically created or "Peppa drinks bleach" kinds.
For example, while there are a ton of real Fireman Sam videos, there are also many that are just an endless concatenation of action scenes from different episodes. It goes on for about an hour, instead of the ten minutes of a regular episode. If you take it away from my kid he gets angry, if you don't he'll probably fall over from exhaustion after a while. And in any case I don't want him to vegitate in front of a nonsensical video for so long.
There are also tons of unboxing videos of toys. There are videos where some guy plays with toys and acts out new episodes with his weird voice. You never know if it is for children, or a satire/joke video for adults.
Then there are just videos that are buggy, stop early, have random parts cropped... etc. and are just frustrating.
It would be trivial to hire a couple of students and find and flag all of these videos (though not all mentioned in the posted link). DMCA and copyright would provide an easy mechanism to remove this content. Adult TV shows that are uploaded are removed immediately.
I have a sinister theory about this: This is tolerated by the copyright owners, or at least someone in the content distribution chain. The goal is to frustrate people enough that they will ditch YouTube and buy the DVDs.
I have since started to create a curated list of the good videos, and also moved to a Kodi setup where I can put known good episodes - it helps a lot to control the quantity and increase the quality of what the kid is watching.