No one is trying to define sex via testosterone. Please point out a specific case of anyone, anywhere saying that the athletes in question or those with high testosterone levels are not female. No, they’re trying to figure out who should be able to participate in particular athletic events, where participation rules are defined in such a way as to encourage competitiveness, and historically have been defined in a way aligned to notions of physical gender, but now need to be tweaked given the emergence of ambiguity.