Welcome to the Community 
As you are new here, I’m not sure how thoroughly you have browsed this place, so just for your information, Fairphone seems to be about to release a new product very soon:
This is not to say that the new thing will be available at the same time with /e/OS. And also the the FP5 is not becoming unusuable the same day either, of course. 
After all I plan to keep using my Fairphone 3 running /e/OS, too. And the remaining FP5 stock might see another price drop once it has a successor device.