Many parent control apps are more like Spyware and are often also exactly that, Spyware which spy on your Kids. Or Google Family Link is also a great example which you can’t remove even if you want too (as parent). I already setup a non-child-friendly blocking DNS and set the Age Limit in the Google Play Store and did all the Privacy related stuff, but I’m still thinking how can I make a Android phone more secure for children? The threads I’m talking about are non-child-friendly content, malware, scams, etc.
It’s unfortunate but in some cases you do have to accept trade offs to get what you want. Not to mention apple has that built in, while much of what’s being recommended here are custom roms and other things that are not exactly user friendly to run out of the box.