I have a pet theory about increasing phone sizes
> Screen size is area (x^2) and battery size is volume (x^3). As battery life is a critical feature, a bigger screen supports (a nonlinear) better battery life.
This does not square with especially Apple's unending obsession to make phones as thin as possible. Which is doubly stupid when it makes them so fragile that the first thing you do after taking it out of the box is to wrap it in a thick rubber shell.
I think it’s even better than that. Your cellular modem (on all the time) scales at O(1) with phone size. Same for on-board tasks that do not involve the screen. Powering your RAM (also on all the time) is similar, but larger (more expensive) phones may tend to have more RAM.
I had a Sony Xperia Z1 mini, that was close to the size of a SE but had double the battery lifetime.