Some of the people on this site are a little slow.
Do you know what an age graded race is? They handicap the performances according to someone's age. Of course, a 70 year old running an 17:00 5K is a world class performance because of the intrinsic limitations imposed upon a person by a 70 year old body.
Now do the same for talent. A 30 year old American growing up in suburbia, wearing shoes all their life, having two parents who weren't very active and don't have an ideal distance runner's muscle fiber composition, eating fast food and other processed goods, playing video games all the time, and one day deciding to take up running 5K's has a bit of a handicap compared to the Ethiopian growing up without shoes at 8,000 foot altitude with a champion distance runner as his mother and a ridiculously high VO2 max.
No matter how hard the first runner trains he will never run as fast as the well trained second runner. So, handicapping things according to factors beyond the runner's control (such as talent) who would be better? If the American had the same VO2 max and basic speed, would the race results show he had worked just as hard?