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.
That’s very understandable. Unfortunately, I don’t know of anything as reliable and fully-featured as Family Link on Android, and I don’t think accomplishing that is even possible without baking the tools into the ROM.
If you don’t feel comfortable with Google’s solution, maybe consider going for iPhone. Apple is a pretty shitty company but at least in terms of privacy they have a relatively clean record for a megacorporation.