I'm an SRE who never worked on YouTube and a parent of two. From what I gathered, YouTube Kids is made by passionate people, who are trying their best. But the question of "is this video good for kids" seems to be genuinely hard. Hence, I prefer to show my kids videos that I had a chance to curate myself. In a pinch I will let them watch YouTube, but only if I'm in range to preempt once they leave the range of sanity for their age group. I still strongly prefer YT to TV though.