Earlier quoted context omitted.
> completely destroying internet anonymity. Stores that sell age restricted products already can also sell "adult passes". Each adult pass costs less than $5, and contains a single use scratch off code that you can use to prove you are of age. When you want to sign up for social media or porn, you need a code. Mutiple companies can implement and sell them.
There would be a huge black market of selling to the underage immediately defeating the purpose.
Most people here should be engineers or at least analytical. No solution is 100%.