Sure. I don't disagree with that. In fact, that's how it currently works on Android, more or less. It's actually looser now than it has been in the past.

But "informed choice without technical ability" is not a thing. You can't be informed if you don't understand what you're doing. People online that more or less understand computers but don't necessarily understand how other people interact with computers tend to miss how this works. My mom doesn't choose to take risks or not, she won't read what's on the screen and if she reads it she won't understand it, and if she understands it she won't trust it, because she doesn't have the knowledge to distinguish a genuine message from the OS trying to ask for confirmation from a janky physhing request.

My mom thinks Whatsapp messages can hack her bank account and freaks out every time her phone asks her to reboot for an update. She doesn't have the time or interest to get to a place where she can change that, and more to the point she shouldn't have to. It's prefectly fine to buy a device that will only let you do the things you want to do and won't let you do the rest.

As you say, that device just needs some process by which someone who cares and knows how to do more stuff can reclaim full access.