I have a FP5, and love it. Yes, of course I wish it had a headphone jack.
Dual sim for my two countries I use it for, plus no sim tool needed to change hardware sim is a nice little plus.
Replaceable battery is dank. It's small and light enough to toss in a small bag if I'm going somewhere and I honestly basically never think about my battery life now.
All the rest of the hardware is pretty good. Not amazing, you can get more for the money, but also it feels good to have some morality in it. And I don't want to break it bir the peace of mind that if I do it's an easy repair, fantastic.
I hated the Fairphone case though. Terrible POS. I got a random internet one and it's much better.