I think a lot of people active on this forum donāt fall into that category - but maybe the majority of FP owners might still. But they probably wonāt appear on this thread, then. 
Personally, I work on a laptop which is now seven years old, and over time added the maximum amount of RAM, replaced the HDD against an SDD, and the battery. I also crunch numbers on it from time to time, but usually send harder tasks off to be parallelised on one of the workstations (with 16 cores and 96 GB of RAM). Suits me.
There are two reasons why I would replace my laptop - and I will also replace my Fairphone for analogue reasons:
a) I run a recent iteration of OS on my laptop. When I canāt run current software and a next-to-secure OS the laptop will have to be replaced. (Even today, my admin would probably not allow XP machines to be in our domain. Iām not going to find out.)
b) When I have to replace the battery again and canāt get one which suits me, the laptop also has reached itās EOL. When I replaced original battery, I was really upset that I could not get a spare original for a decent price. So I bought a retail version and went down from the original 8+ to below four hours of working capacity, which was a bummer. Now, I canāt even get an original one any longer, since the manufacturer went on and is using a different kind of connector. Screw that.
When the same happens with my pocket computer, aka Fairphone, it will have to go. OS and battery are key components. Keep them replaceable, and the phone will last.