Systemic discrimination against Black Americans both historically and today is well documented and understood. I could have written a long preamble about the many elements of society that factor into racial disparities, but I assumed I could skip that for brevity since everyone on HN is already well aware.
You need to look at this data with an intersectional perspective. An overly generalized label of just "Black" as an identifier does little to help and may actively mislead in certain situations. Considering multiple attributes- race, educational attainment, location, industry, job function, seniority, etc is critical because the intersection of these may cause dramatically different experiences.
Consider this example to maybe make it clear. Imagine a gay man pursuing a career as a Broadway dancer versus a gay man pursuing a career as an elementary school teacher in Alabama. Will being gay have the same risks and challenges for each man? Is it fair or useful to try to group their experiences into one "score" for if that attribute is an advantage or disadvantage?
An average white, male employee might accept that their mid-level, unfulfilling but acceptable cubicle at eBay is as good as they're going to get and stay for years. An otherwise identical minority candidate will be getting 10 recruiter messages a day for better opportunities.