How do you propose getting “informed” consent from an audience who doesn’t care and willingly expose everything about themselves and everyone they know to find out which Star Wars character or 80s pop song they are most like? Genuine question, as this doesn’t seem the least bit a solved problem anywhere.
Usually, solutions in this area generally have a couple of characteristics: the first is that the "secure" case is generally useful for 95+% of people, to the point that they might not even know that there are other "modes" that are more permissive. The second is putting surmountable but significant barriers in place to prevent disabling these features, in an attempt to prevent casual/unintentional deactivation. Strange key combinations that lead to scary text and wiping the device seem to be fairly effective in keeping out people who cannot give informed consent. And a third is allowing a user-specified root of trust: for example, one can imagine an iPhone that is every bit as secure as any other iPhone today because I have enabled all the security features, but it's using my keys to attest against instead of Apple's. There's a lot of interesting work being done in this area: one I personally like is Chromebooks, which have the dual purpose of being secure, "locked-down" devices for general consumer use, but also for being useful for development work. And there we're seeing interesting solutions such as using KVM to run an isolated Linux, developer mode, write protect screws, …
Nobody said anything about clumsy people. As one of many examples, look at all the guides that tell folks to disable SIP and don’t explain the risk and really don’t even need to disable SIP, the app should just be fixed properly.
There are exceptions of course and good reasons to disable it, so I’m glad Apple has the option, but I’d venture to say 85% of the time it’s done by a person who isn’t really making an “informed consent”.
(Focusing on user consent obscures the actual problem; people often consent to running malware. What matters is whether the software to be run is useful and harmless.)
Ah, but not in an informed way–users don't typically run software they know to be harmful/useless :P (And no, telling them that it is harmful isn't apparently enough to inform them…) But I agree with the first part.