You can control a lot about how platforms specifically work with legislation. After decades of seeing how they function we are more than capable of accurately identifying what functionalities are deleterious to the well-being of people generally or children specifically, what should be under the control of the parents of children, and therefore we have a good idea of what we should legally require platforms to disable or otherwise put under the control parents.

Again I propose as an example: having an account marked as a child’s account, with a designated parent account and making it so that if someone would attempt to add that child account as a friend or connected account on a social media network such an addition must be approved by the parent account.