I disagree strongly. The low standard of living of huge amount of black people and the lack social mobility refute this. Just because there are black millionaires (there is sonething of an established black elite who look down on poor blacks)which creates some kind of average doesn't mean that average exists. There are ones in the middle of the social order of course but way too many living in trauma in housing projects and other forms of segregate housing.
So people haven't come out of those projects to become black millionaires?
Name me one place in the world where black people have a higher rate of social mobility?
Name me one other place in the world that gives you a better chance, regardless of race, of succeeding granted you finish education, get a job and wait till marriage for kids.