Personally, I had not heard of this new system You.tube will be implementing until you brought it up here, so I'm not too knowledgeable on this.
However, I can say that the AI system will fail terribly, whether it be the actual AI or the system as a whole.
For one, if all the system uses to come up with a user's age estimate is the content they watch and their account age, I already see a few flaws.
First, people of all ages watch all sort of content and content creators that may not always be what's expected for their age, whether it be a grown man watching someone play Minecraft, or a child/teen watching cartoonish videos on someone's everyday life (plus the fact that I've known You.tube often mislabels the age group a video is meant for).
There's also the account age issue: If someone, let's say an adult creates a new account for whatever purpose, but usually watches content usually geared more towards kids, their account would then be restricted just on those facts.
Now, sure, said adults could just scan their face, provide an ID, or a credit card to remove the restriction as you stated. Aside from the privacy issues with providing such information to an app/site that should have little to nothing with it, more questions arise.
Although not everyone, some people tend to look on the younger side, even if they're adults, and some children tend to look older. I imagine the AI isn't perfect so it could also misidentify one for the other and cause more issues than it's meant to. As for the ID and credit card solution to the restriction—it's been seen time and time again that children can simply get their parents' card without them noticing and use it to bypass the issue.
Quite frankly, I believe this new AI system You.tube is quite useless and will fail terribly. If the issue is about having minors on the app and restricting their content, it's more of a parenting issue than anything.
Personally, I've been using You.tube less and less as time goes by due to other social media apps, having a life, etc., but I still use it occasionally. If I have to stop using it because I'm flagged as a minor, so be it. Although, I do have multiple accounts and devices so I could probably bypass and move to one of my other accounts. I also don't mind using one of the methods mentioned above to remove the restriction, this is the internet after all, there isn't much privacy to be had, and I also couldn't care less. Knowing myself though, I'll probably continue using it.
Basically, I may or may not stop using You.tube (if restricted) depending on my mood, and just in case I forgot to mention: this new system is terrible and will fail, if it hasn't already.
