It's only cheap relative to Apples other phones, it's still outside of the range I'd consider reasonable. Although it seems the reason most people spend so much on phones is to get better cameras? Which I'm not particularly bothered about - maybe it's worth it for that.
I've upgraded my iPhone five times, just recently to the SE, and each time it's been exclusively for the camera. Literally exclusively, since in many other respects the functionality is going in reverse (loss of home button, touch ID, headphone port, etc.) I swallow it all for a better camera.
Yes, but no reason then to upgrade your phone to get a better camera at premium prices.
How about using the camera phone if you are strolling down the street and want to make a Pulitzer photo and getting a better camera for those times you know you will be making photos like an anniversary, etc.
The thing is: look how much we love convenience! Instead of having two devices (a decent phone and a much better separate camera, both rarely updated) we prefer to constantly upgrade the phone to have a better camera.
But a lot of the times you know you will be making photos in advance. If you go on holiday or you have an anniversary, etc. there's not that much planning required or bother to bring the proper separate (compact) camera.
I have a 16x20 print on my wall from a 6x7cm negative I took with a Mamiya 7 camera and lens. The print is sharp even under a 10x loupe. This was an image I envisioned in my head, waited for the right time and light, set up on a tripod, took 3 exposures, developed the film and printed with an enlarger.
Still, 80% of the pictures of my kids are on my phone, since the moments pass in an instant, and my phone is always with me.
It's only cheap relative to Apples other phones, it's still outside of the range I'd consider reasonable. Although it seems the reason most people spend so much on phones is to get better cameras? Which I'm not particularly bothered about - maybe it's worth it for that.