Real question is....
Why are Euros able to be successful but American whites can't?
White females are doing OK in college/WNBA, but white American boys can't?
When was the last time a white American was an elite 2-way player like a Kobe, KG, MJ, Hakeem etc? My theory is that brehs leveled up their outside shooting, so the GSWB ("good shooting white boy") lost his edge. Euros learn the game early and develop the skill advantage. Blacks might come up in AAU and need skill development...but brehs got enough athleticism to get by until they get caught up to the pro game (or they come in ready like Bron).
Seems like white dudes abandon any sport where brehs start to dominate. Football is the exception because the leadership structure does everything to protect white male dominance over front office/coaching. NFC East got all Black QBs now....so even that advantage is going away. Latinos got baseball/soccer.
But they kind of made a comeback in other positions.