I think that there's another element to some of the automated content channels like "Toys in Japan". They make content based on comments on other videos, was hacked according to Goodwin's Law. (https://www.youtube.com/watch?v=3OoU2ck2RiY)

My pet theory is that these channels are monetized for automated click farms and they use children's content partly because kids will watch it, obfuscating the bot-clicks, and more-so that they can increase the safe threshold of bot-clicks/bot-views since children's viewing habits are to watch the same video repeatedly.