> It should be “is this a child-locked device?”

No, that leaves vulnerable adults unprotected. It should be "Is my thing in one of the categories of things that this device says this user is not permitted to do? If so, I shall not permit this user to do the thing.".

Nothing stops software authors from providing pre-built bundles of categories that they believe fit certain types of vulnerable people [0], but the fine-grained control must be there so that guardians can choose to set things up for those they guard so to adequately protect them while minimizing the amount of stuff that they're blocked from.

[0] Like: "Overly-trusting human who needs protection from scams", "Dementia-damaged adult who cannot be trusted to manage their finances", "Median sixteen year old USian", etc, etc.