Is your mom also terrified of the phone, because Apple can't supervise every call? Does she get cagey about opening Safari because there's nobody checking every website for scams?
The iPhone is already dangerously capable, Apple can't have their cake and eat it too.
My response was wholly based on my own observations. My mom sends me stuff from online all the time, I've watched family members and friends install emulators and YouTube alternatives like it was riding a bike. I'm very sorry if your social circle has forgotten how to do these things.
The only person I've ever known who exclusively used Apple-native apps was my ex-boyfriend who wrote Mac software. I've never known anyone else who refused websites or calls on the basis that Apple doesn't review it - I think that mindset is far in the minority.
The iPhone is already dangerously capable, Apple can't have their cake and eat it too.