I don't really see why targeting the company is useful other than for political practicality because it's rather easy to hold entire companies accountable than

I don't really see why targeting the company is useful other than for political practicality because it's rather easy to hold entire companies accountable than some manager hiring for some specific IT role in small enough numbers its harder to not give them the benefit of the doubt. For starters, if you don't care about what job role a diverse group lands up in, does that mean it's okay if they don't get any upper level well compensated jobs so long as they're staffed in many lower paying jobs? In regards to avoiding discrimination, and giving everybody a fair chance, I don't see a system that accomplishes this besides a lottery. The job interview is fundamentally a ritual of discrimination. The entire fixation on increasing employment for a small number of "diverse" groups is mostly driven by the political strength of said groups rather than any sort of consistent moral principles.