A primary function of schools is to rank and sort and when they lose sight of that they fail.This is exactly what has happened in the United States. We have abandoned the necessary mission of evaluation and direction for a politically correct but intellectually vacuous mantra of "anyone can do anything". And for whatever reason, probably in no small part due to guilt, parents support this silliness. While these same parents acknowledge levels of ability (and inability) in sports and will even concede their tennis playing child will never become the next McEnroe no matter how much they practice, for some reason they are quite confident their child should master Geometry to the "A" level.
And our schools have been more than happy to please. Previously difficult subjects, like Geometry, have been watered down to the point that the village idiot is now on the "Path to Excellence". The only thing shoveled out faster than "A"s is self-esteem which we are so wrapped up in that it is a cardinal sin to grade papers in red ink. Challenging students to the point that most earn a "C" and only the top five percent warrant an "A" is not discouraged, it is forbidden. At this point American public schools, and the diplomas they print, offer no differentiation whatsoever to distinguish one student's "academic accomplishments" from any other.
Until we have an education system where distinctions are made, where children are properly and professionally advised and directed toward appropriate programs, trade or professional, the United States will continue to devolve.