Yup I remember the V-Chip. That was similar but just different enough that it made more sense that it never took off. That would have required adding a module

Yup I remember the V-Chip. That was similar but just different enough that it made more sense that it never took off. That would have required adding a module to all televisions that would incur cost and would have also changed which entities in the television industry had control over their content. That industry has always been plagued by layers of bureaucracy. The internet on the other than has let website operators have more freedom to govern themselves with some exceptions. I think in this case implementing RTA headers while it would have some cost it is leveraging existing code, web and load balancing platforms and just bringing back header checks in applications which many apps already know how to do and then calling the parental checks that also already exist in many devices and in some cases the UI is just hidden.