I think there are three big reasons for professional/corporate success.

1) Leadership

I have noticed white young people are given opportunities to lead and take on responsibility at a very early age. People trust white leadership. Are they more efficient? Do they double check mistakes? Is this a slavery carry over? Overall, even in largely black orgs, white people are in leadership positions and expect to lead.

2) Mentorship

Most white people who earn high salaries have mentors who guide them. Learning how direct people, delegate, be neutral during conflict and solve problems are very high level skills that must be learned through experience.

3) Networking
I know people of other races, not black or white, who are also doing very well. They network, let other people know what opportunities are available.