The US needs to raise its standards more than a bit for the average to be world class. At present there are no standards. In the same state, one school district might spend three times more than another, and have three times as many students reading below grade level.
If the standards were up to world class, then there would be no reason to "bother" those above the median, as they would already be producing graduates that had complied with the minimum or better.
You are playing silly word games here.
The fact is that most American schools are far from being able to yell "We're number one!" and wave their giant rubber fingers.
The difficult part is testing to assure the standards have been met. Multiple choice exams are the usual way, but they are far from being adequate.