The only device mandates that should be taking place is for the default installations of web clients should be checking to see if parental controls are enabled. This only impacts the major browsers. An intern at each browser company could add this check in minutes. If they are enabled and the person logged in is on a regular account (not admin or power user of sorts) then the base installation of web clients must che…
This can also be broadly implemented, any other technical solution won't be widely spread anyway.
I don't think authorities care about child protection though. They could have legislated malicious advertising practices and a lot of similar bad influences, but didn't.