It's important to understand that "age verification" schemes being passed by states, ostensibly to "protect the children", won't do that and will bring about incredible abuses.
In order to age verify children, obviously EVERYBODY of any age must be verified, for every account, under every name or pseudonym, ultimately on every site no matter how public or private the topic, and before downloading any apps.
Children will find ways to work around this. They'll use the accounts of adults, which will be openly traded. But because these age verification systems must by definition be based on government IDs, the verification process creates a linkage between your account names and your actual identity, subjecting you to all manner of leaked personal information, government abuses (think MAGA in charge), and worse. Firms will claim their systems either don't keep this data or can't be abused. History strongly suggests otherwise, and when courts step in, those firms will have to do what the courts say, often in secret, when it comes to collecting data.
Age verification is in actuality a massive Chinese-style Internet identity tracking project -- nothing less -- and there are many politicians in the U.S. who look with envy at how China controls their Internet and keeps their Internet users under police state controls.