I mean, all of this is obvious. Group-level differences will still lead to the composition of individuals in a given profession differing from the composition of the general population, even if no hiring managers discriminate.
That's not necessarily true, for many kinds of complex sociological, economic and demographic reasons. The nature of the working population is different than the general population. The skills required from the working population vary across time and space, and may very well consist of a set in which different groups vary only slightly. Etc. etc.
Frankly this just reads like a cover story for "I don't want to have to care about this".
Well yeah, it’s an extremely complex system. If we’re just going to leave it at that, then you have no basis for insisting that working populations are proportional to the general population. But you seem to want to have it both ways.