You can literally do most parental controls with your home network if you know what you are doing which means those that don't will have to learn, I know how terrible a parent has to learn something to take care of their child. You can even enforce it outside the house by setting up a tunnel to your home network on a phone and making it so the phone has to use the tunnel in order to connect to the internet otherwise there is no internet access, so your network parental controls are always enforced. Hell you could make it so the phone only gets internet access when home too, to enforce even more limitations on internet access.
Yes this will require constant updating as things change and you discover workarounds and new apps are developed, but as a parent aren't you supposed to be constantly learning and adapting for your child anyways? You may even need to buy some gadgets too which again is nothing new for a parent to do to protect their child.
This shit can already be done but lazy parents and shitty governments are going to make it everyone's problem.