It doesn’t. Kids are the ones to whom videos need to be restricted. Adults should be able to watch both kids and non kids videos. So the only thing needed is

It doesn’t. Kids are the ones to whom videos need to be restricted. Adults should be able to watch both kids and non kids videos. So the only thing needed is for creators to mark a video as “for kids” and the algorithm to confirm that it actually is for kids. Nothing else should even be available for kids. If they want, they can have an additional option for creators which is “definitely not for kids”, much like you’d have an “explicit” option for music. These wouldn’t require an algorithmic check and simply not be available to those under 18.