Please don't do this. It would eradicate internet privacy by forcing all internet users into giving up their personal information to use the internet, making everyone vulnerable to hackers. In our modern day and age, it is necessary to use the internet to navigate the real world. Social media as it currently is sucks, yes, but this is not a solution. It will have a negative impact on everyone, including the children it's supposed to "protect".
I would like to start by highlighting the impact on the group of people these bills are supposed to be for: children. While social media can certainly have a negative impact on children, this is mainly due to the nature of social media algorithms than it is due to the inherent vulnerability of children. Many children, especially those trapped in terrible situations of abuse and bullying in real life, have a positive experience of social media, which allows them to express themselves and access support that they couldn't have in real life. Take, for example, a gay child in an abusive homophobic household: social media allows them a world where they are accepted for who they are, which they would never have had if a social media ban restricted their experience of the world to what their parents believe and nothing else. It is impossible, in our society, for a child to leave the house alone, or even to report their own abuse, as children's phone calls are increasingly monitored by parents and it's impossible to report abuse in person, as schools involve parents and they won't be allowed to go anywhere on their own to seek help from police. Banning social media would strip these children of some of the only support they have. Secondly, this kind of all encompassing ban harms disabled children, who often cannot leave their homes often due to their disabilities. For these children, social media and messaging apps can be their primary way of communicating with their friends due to physical restrictions. A social media ban would deprive them of social interaction. Finally, restrictions on the internet would negatively affect all children due to the neccesity of internet use to participate in society. Schools, often, set assignments that involve watching youtube videos or researching a particular subject. Restricting children from youtube or searching up "black box penetration testing" without proving they're over 18 harms their education. Many educational courses for children and teens are held online now, with work to be submitted on social media like Facebook or Instagram. What happens to these, when kids are banned from social media and adults cannot use it unless they verify their ID?