The phone itself looks like a pretty insignificant portion of the total equipment cost. Why would you use an iPhone instead of an full camera at that point?
Yes, a phone is a small part of the cost in this set up.
An actual film camera instead can be much, much more per day.
In reality no one other than apple is going to have high end professional light rigs and a phone camera. But plenty of people could use the money they aren't spending on a "proper" camera on better lighting instead and perhaps get a better final product than the historical configuration of "we've spent a tonne renting the camera, let's see if we can afford any lighting".
An actual film camera instead can be much, much more per day.
In reality no one other than apple is going to have high end professional light rigs and a phone camera. But plenty of people could use the money they aren't spending on a "proper" camera on better lighting instead and perhaps get a better final product than the historical configuration of "we've spent a tonne renting the camera, let's see if we can afford any lighting".