You join a club and train from childhood, practice time takes a primary focus. Kids learn fundamentals and how to play as a team.
The US has kids join AAU leagues and play 4x a week while basically never practicing. They focus on ball-skills and iso ball.
Kobe talked alot about this, and Kevin Young has brought up how the NBA is different from College in this way, but the issue goes all the way down.
It won't be long before the US isn't dominant in basketball. The best players in the world aren't American, and in a generation the US National team will struggle to Medal in the Olympics.