Family Link. You can whitelist apps, get screen time stats, and if your kid needs an app, when they try install it it will ask your approval.
https://play.google.com/store/apps/details?id=com.google.android.apps.kids.familylink
Bit of a pain getting the accounts setup, but otherwise works very well for preventing my grandma filling her tablet with junk.
That's just what CMG claimed to have.
But to be useful for an advertising network, it kinda needs to be installable on everything. And if it failed to suppress the mic LED on a single device, it would be very easily noticed?