I think I had this all wrong. Fairphone isn’t / doesn’t want to be an enthusiast DIY brand at all (like framework for laptops) but a mainstream brand that’s eco-friendlier* and non-exploitative.
So of course they will not care much about niche features like other ROMs or audio jacks. The privacy focused, tech-savvy or feature focused buyers are not their target.
*IC and PCB related footprint is still roughly 80% of the FP4 and FP has little to no control on those processes, according to an independent study.