"If the new system incorrectly identifies a user as under 18 when they are not, YouTube says the user will be given the option to verify their age with a credit card, government ID, or selfie. "
> We will use AI to interpret a variety of signals that help us to determine whether a user is over or under 18. These signals include the types of videos a user is searching for, the categories of videos they have watched, or the longevity of the account
For example, account created less than N years ago searching for skibidi -> probably teen.
Google probably has enough pictures taken with the person's phone's camera and recordings taken with the phone's micrphone, along with all other standard data sources like browsing history, searches and so on. There also likely are similar recordings from friends, allowing to properly profile them, with their respective positions in their networks.
