And I think that's probably what the OP meant by "better at running". The vast majority of people can run to some extent, so the assumption is that someone is "better" at it usually means "faster". And the obvious place to look for evidence of that would be in sporting competitions, rather than trying to look up metrics that you have described. Obviously its a simplification, but if you don't do that then life would be far to complicated and detailed to navigate.
Do people have no sense of history here? The internet lets you look up all sorts of things, like how the racial composition of US track and field has changed over the 20th century, or how Paavo Nurmi (a poor guy from an underdeveloped country) dominated distance running in the 1920s, challenged only by another couple poor guys from underdeveloped Scandinavian countries. It was clear from publicly viewable sporting events in the 1920s that Scandinavians are really the best at running; east Africans really didn't figure into the competition.
Is it fair though? Is it supported by metrics of muscle strength and length etc? And does it take into account the differences between blacks (Africans?), west vs south vs central (pygmies!).
Also, there's the possibility that whites of equivalent athleticism find better options for their life than being a professional sportsmen, the bottom 80% [1] of whom end their career at 30 with little to show for it but lifelong injuries.
[1] made up statistic.