> Frankly, I'm not sure what they'd get out of root at this point.

A permission that allows them to hide that they have access to everything, including other apps' data?

Possibly. Yes, hiding from auditing would be a possible advantage, but I think an app with accessibility permissions could already draw over the settings app to hide the real list of permissions from your view without root. Off the top of my head I think there's a whole mess of permissions needed to allow that, but we're discussing a threat model where permission dialogs can be effectively bypassed so that's no obstacle.