You can be unbiased in hiring and still end up with an unrepresentative mix, because underprepresented minorities don't even apply, and outreach is a good way to get to improve that without lowering your standards. That's the theory, at least, but yes, in practice it's really hard and most of these efforts end up performative, and staffing DEI bureaucracies with minorities is a good way to make the dismal diversity statistics look less bad if you don't look too closely at the breakdown by roles and salary bands.