People throw this accusation around all the time, but it doesn't make much sense. Outcomes are the only holistic way to measure opportunity.
If you're seeing one group getting lesser outcomes, there are only two possibilities: Their opportunities are being artificially limited somewhere, or one of the groups is simply better than the other. So if you really believe this is a meaningful distinction to draw — that measuring outcomes can't tell us about opportunity — what you're really saying is, "The groups who haven't traditionally been in power are in that position because they are innately less capable."