locked behind a simple menu setting
It's not simple, on iPad anyway. There are various layers of menus and options and some aren't as 'blanket' on/off as they appear
looks about as functional and non-broken as it can get
iPads, at least, can't even accurately track usage time in their own device. We've got time limits set on overall device usage time and specific app times, and it's woefully inaccurate, and that function is part of the same 'device control' app / settings area that looks after lock-down settings for in-app payments and new app installations etc.
That's why I've removed any credit card details from the Apple account.
>Why can't app vendors (and in particular their middlemen who manage the purchases) make even a minimal effort at not having this system be broken by default?
Apple put an effort into making it all locked behind a simple menu setting, which to me looks about as functional and non-broken as it can get. I don't know what more can one expect from a company, aside from being able to read the mind of whoever is using the device at the moment and automatically adjust permissions based on that.