@silverwizard when my son was younger (he is 12 now) we had regular conversations about why a movie or a network service will remain locked by the parental controls. With time, as he inevitable became exposed to more and more content above his age (some of that done by me, after assessing his emotional and mental capabilities) - games or movies most of the time - after another conversation I started lifting some aspects of controls above his age. And we continue the process.
I think the point I am trying to convey is - be transparent about why some things are locked. Talk to your kids (when they're older) to know their experiences form elsewhere. Adjust settings. Support. I think I got it all quite well with my boy - not ideally but well. We still argue, he still tries to outsmart the system sometimes...
Ah, one thing: Android and Google Apps - do not enable any google apps for your children as embedded webview does NOT fall under any parental controls. Finding out Youtube playing through google maps was quite interesting.
Android parental controls are not effective at all, chrome and otherwise. It a steaming pile of horse shite.
Apple does a bit better but requires some fidgeting to be set up properly. But does work, most of the time.
For anything else, other devices, I have a per device ACL list on the firewall...