My first iPhone was the iPhone 3 and I now have a 5. I had kinda figured I'd just stick with the odd-numbered models but the iPhone 7 announced today doesn't give me a whole lotta motivation to upgrade. The camera is better (they say), there's no more headphone jack and it interfaces better with the Apple Watch. Other than that, I don't see a whole lotta difference.
I tend to use an actual camera when I want an actual photo of something, only using the cellphone camera for emergencies and to take visual notes. I don't like wearing a watch of any kind and I only use headphones on airplanes, which isn't often lately. So I may just wait for the next one, which doesn't appear to be far off.
You'd think they'd make an effort to include one cool and new must-have feature in each new iPhone. I might buy a 7 if it could tell me when the 8 is coming out, what's it going to do that the 7 doesn't and why it's going to cost me a lot in new accessories.