> And why isn't there a "Content-Rating: sex" or "Content-Rating: gambling" HTTP header? Or something along those lines? Why isn't there one easy "under 12" button on a phone to lock down tons of stuff, from PornHub to gambling sites to what-have-you? All of this is also a failing of the technical community to actually build reasonable and usable standards and tools, too.

The mobile app world solved this years ago, and successfully generates age ratings for different countries based on developer interviews. (It's part of the app submission process).

There are problems with the mobile app world, but that isn't one of them.