As stated advertising on children's videos is legal and commonplace, so singling out yt is a little weird. The whole situation is a bit of a paradox to be honest.
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.