It happened on mobile because Android (dunno iOS's permission model well enough) is more on the developers' side than the user's side, or at least they're more concerned with everything just working (for some values of "just work") than with giving users a chance to make sure that things don't work that the users don't want to work. A fine-grained capacity system where users were given the option to lie to the software about what capacities it has wouldn't be perfect either, but it would remove a lot of the user-focused pain points of Android's permission model.