Advertising on children's videos ensures that children are probably the ones clicking those ads- thus YouTube ads lead to tracking children.
I do agree that singling out YouTube is strange, but it definitely got people to click.
[0] https://support.google.com/youtubekids/answer/6130541?hl=en
That app was, at least when my kid was in that market, a hobbled app with its own significant problems.
YouTube’s issue here are all about how they funnel kids to profitable content.
What do you mean "singling out"? They're the biggest advertising company in the world.