Revenge of the machines
Our experience has been that you can't let kids watch online video unattended. The algo will just keep choosing new shit to watch, which gets shitter as the chain of association gets longer. And little kids will watch anything.
Later on in the growing up process, a not inconsiderable problem is an education system that is neither equipped nor designed to teach critical thinking. If you watch random YouTube, then you are probably neither designed nor equipped to teach this to your kids, either.