Which model? Was it the FP1? It sounds like your friend was extremely unlucky - FP2 is 11 years old & there's still (a limited subset of) parts for sale for it (display & camera). FP3 (7yo model) still has all the parts for sale.
That said - I'm critical of another aspect of device longevity: software support. I upgraded from my (still working) FP3 to the FP5 because apps I needed stopped working on the highest version of Android supported by FP3. That Android version is still officially supported by Fairphone & receiving security updates but without major version upgrades the app support can be problematic. Obviously that's ultiamtely the fault of bad app devs, but ultimately it's hard to overcome.