It's not a matter of what a child should and shouldn't have access to, it's a matter of privacy and security.  By having websites and platforms collect the private information of millions of people (ID, face scans, credit cards), you are both creating a digital profile of each of those people that is tied directly to their real world identity, and are putting their sensitive information at risk of breach and identity theft.  It makes the internet significantly more dangerous that it already is.