Two focal lengths at the same physical distance to the subject have exactly the same perspective (i.e. if you crop them to the same area they will look the same). There is no extra information to be had from that.
The depth information that can be obtained from differences in angular position/size of objects within cameras' FOV. There's a reason a photo taken with a 28mm doesn't look the same as with a 50 a few steps back.
Exactly. The steps back change perspective, not the lenses. That’s what I was trying to say above. In the iPhone both lenses are at the same distance to the subject.