I would say probably the FP6 if you care about sustainability, fair materials and working conditions, etc. It also seems to be a solid phone with decent cameras and performance, though with a higher price than phones with equivalent specs due to the first point. The FP cameras have improved a lot since the 3, they seem very usable in the few reviews I’ve seen.

I will say that, since you care about both battery life and camera quality, you might want to check out the Xiaomi 15 if it’s available at a good price. I’m certain Xiaomi doesn’t have the fair working conditions and materials like FP does, and they definitely don’t aim to make their phones ultra-repairable.