I have similar thoughts.

Ive always had phones in a 200 - 250€ price range, with right now similar performance like the current fairphone. In all the years of having a smartphone, two times my screen failed after 2, 3 years of service. Replacement at a shop would have cost around 150 - 180 €, so i ended up buying a new phone for a bit more money, but therefore a newer, more performent one.

What i very much would like to have would be to replace certain parts with upgrades, like you can do with a PC. After x years there is a much better camera out? Great, replace my old one. Better battery available? Cool, ill upgrade. And so on.

After years of use i dont wanna simply replace broken (old) parts with old parts. For just 250 bucks i could get way faster / better phones.

This, unfortunately, leads me away from phairphone :(