It's slightly more than that. These sports (and let's include hockey, since it's played widely intentionally too) are all organized the same way, meaning the players are largely trained the same way leading up to college and also in the pros. There's a clear pipeline to the basketball and hockey national teams. The best league is the one closest to home. The uniform pipeline and playing close to home makes training for, coaching and playing with the national team that much easier, which makes the team that much better.

American men gotta find their own way to become a world class soccer player. There's no pipeline like there is for the big 4. It's harder for teammates to gel when some went through the ranks in Germany, some in England, some in Italy and have only a few weeks with a new coach to buy into the system.

America's biggest rivals also aren't very good. So while the best European and South American teams constantly have to play each other and fight for survival, the US has to play middling teams like Mexico and Canada and tiny Central American and island nations.