Initially it was building out the basic feature set. Now it seems every time they add a new swipe or icon it breaks my mental model of how my phone works without adding something that I needed.

Apple is caught by their own success: the iPhone is mammoth hit but they've reached the end of its growth. So they've got a whole organization built around making it more compelling to grow the sales, but they should really switch gears: put the iPhone into maintenance mode and invent something completely new. Easy to say, hard to do, trillions on the table if they pull it off.