It depends on the level of involvement you're comfortable with. As far as I'm aware, Fairphone are partnered with a Chinese ODM T2 Mobile for the hardware portion of their smartphone products. You can expect they are sourcing the hardware and spares, SoC/subsystem BSP components, peripherals and associated firmware from T2Mobile.

Independence from the Chinese manufacturing hegemony probably means opting for a flagship Samsung, 11-series Pixel or pre-2025 Sony flagship.