Society has had laws in place to prevent children from viewing things they should not be (inappropriate movies, magazines, etc).
On the internet it is much more difficult, of course, and we can't realistically expect some shady offshore site from implementing age checks, let alone recommendation algorithms. But Google is a public, respected company from a first world country that claims to be promoting social good (which, of course, is marketing BS, and even if it weren't I would not want their idea of social good, but still). You'd think that they would invest some effort into not showing inappropriate content to kids at least. But no, they throw up their hands and go on ideological witch hunts instead.
If nobody gives a fuck enough to affect business you can give the complete SAW series to 3 year olds and all the offended can do is yelp indignantly.
But then I try to not let my mom on YouTube either. Or myself, for that matter.