One interesting thing about the my phone is I managed to crack the screen on the 3 iPhones I had before, sometimes multiple times. I've put this one through hell and back and it just keeps going. I wonder if the build quality (not just features and performance) has been a factor in slowing upgrades...
Personally I "solved" it for my need by having two laptops (I don't have a desktop at home anymore), one is a 15" made for mobility with tons of battery and low weight, the other is frankly more of a "transportable" 17", too heavy to hold it in one hand and lasting less that two hour on battery but with insane power for all my work and gaming need.
Interestingly enough both end up costing almost the same.
If you rely on a "premium product at premium price" you need to make people want to have it, and for them to replace it that's either obseleting the old one, or making the new one
Downside of this of course, is that it's harder to rely on that anymore when you try to grab mass market too.