I feel like phones are currently in the "Osprey backpack" stage of product development. There's nothing new happening and no new problems to solve, short of a miracle like making your backpack half the weight or something. So what they do instead is add features one year but take others away so they can add them back later.

So it's like: year 1: super thin, super light (shit battery life, no headphone port etc), then year 2 it will be: awesome battery life, headphone jack (but thick, heavy).

Basically they have to be careful they don't ever make the perfect phone. They do have planned obsolescence as another trick up their sleeve, though. So you'll never see an Apple phone with upgradable storage etc (the Android ones go more for having the software becoming obsolete).