From the 3rd party data it seems like people are buying the Max because it’s the best iPhone, not because it’s the biggest. It has some genuine battery improvements over the regular Pro that make it worth the extra cash.

At the same time I wonder if the majority of regular buyers are even making use of anything the regular Pro offers.

So why not simplify the product line:
-iPhone 15: last years’ specs in a regular chassis
- IPhone 16: larger display and bells and whistles.