>>151376451 (OP)
Many talents that age don't play U20 football because they are already integrated into "real" teams
But there is a possibility here. Blacks dominate youth football because they are physically mature earlier, that's an advantage in youth systems where everyone already chases success. Coaches often don't have the end product of a player in mind, so they are fine with some giganigga bullying smaller kids off the ball even if he knows the giganigga is already fully grown and not very special apart from that
Apart from that, blacks and immigrants in general are more eager to take the risk of betting everything on a pro career. They have a lower living standards and often feel alienated by the education system. Meanwhile, your average timmy will be encouraged to pursue an academic career since that is the safer option
Apart from that, the game simply has become more physical, more about speed in particular, and more about system adherance rather than individuality
All of that can technically be reverted to a degree. But it's unlikely to happen. So this is probably either pure coincidence or they just didn't use their best players, most of whom will probably be black
Demography itself is obviously working in minorities' favor, they are getting more numerous