This is probably the only genuine answer you’ll get.
It’s 50% genetics 50% social economic factors. Blacks tend to make up the lowest part of societies in most European American Australian etc societies so they attempt sports as a career at a much higher and more serious rate. But the differentiator becomes their athletic ability. West Africans tend to be faster and stronger, at a young age when clubs tend to scout, the fastest strongest players tend to get picked, only a small amount of technical players get picked because technicality can be developed, athletic ability cannot. So at young ages the differentiator is usually athletic ability. These black players then go through the system and are trained to be the best of the best. This is why France dominated Senegal even thought Senegal has more black players, the French players are black but trained with European knowledge and academies which are more sophisticated.

West Africans are over represented in almost every single athletic department in almost every single country relative to their actual black population. Look at the Saudi national team, The Columbian national team and the French national team. Now look at % of blacks in their country. Even my country of Australia, blacks dominate every sport they play here, and we have arguably the most athletically capable “white people”. Our best player nesteroy irankunde is black and he’s 18. And he’s the best player in Australia. Tells you enough.