Probably because developing and making those things is extremely expensive. The "traditional" smartphone manufacturers have far lower per-unit costs because of

Probably because developing and making those things is extremely expensive. The "traditional" smartphone manufacturers have far lower per-unit costs because of economies of scale and because they externalise many of the production costs by using low-paid labour and environmentally destructive practices. (Some "open" phones probably externalise these costs as well, but Fairphone in particular is so expensive because it tries to avoid doing that.) Not to mention that those lower production costs are then further subsidised by the manufacturers' efforts to extract value from the user in other ways. Every time someone tries to make an open/pro-privacy/pro-consumer phone and doesn't produce a perfect product they get heavily criticised, but I think they are up against some fairly fundamental limitations. The fact that there isn't really a satisfactory option out there despite numerous attempts suggests to me that the problem is not with the specific products or companies but something more fundamental. I don't think it will ever be feasible for ethical phones to compete with non-ethical phones on cost.