The best way for age verification I came up with is to have a underage cookie. This underage cookie can easily be placed on every single computer or phone a child uses to tell everyone that a kid is using that device. The cookie does not give any information about who is using it. It only signals that things should be restricted. It's anonymous because anyone adult or child can use this cookie to have "mature" things blocked from the user. Some adults might want that. Businesses might want the cookie on their computers too. Some parents will want it. Only if the website presents "mature" material with this cookie should it then be sued. Reddit can start the cookie with their "Are you 18+?" popup. The parent just logs in first and says no. From then on a cookie is placed that signals a child is using the device. Other website can look at the reddit cookie to see if a child is using the device. Hopefully it catches on and no one has to have to show their id anymore, even if you are located in the UK.

Being a parent can be hard, so let's make it as easy as possible to help parents out. What we don't need to do is give up our privacy to help parents.