I believe you've aptly described the USA's educational dilemma, too, except that the separation of students into social groups at age 7 isn't so pronounced. The neighborhood school concept and the private schools for the wealthy are what separate things socially in america.  

I've noticed children of relatively wealthy, intelligent, well-educated parents who've come only slightly smarter than dirt out of the educational system in several places in the USA. I also noticed, as I did research all over the USA as part of my earlier employment, that schools simply do not teach those things that once were taken for granted in schools during the first half of the twentieth century. Then one could choose among Latin, Spanish, German and French for foreign language studies, and most schools in your average-sized cities had extensive programs for art, music and theatre. Many had their own swimming pools.  

For all the money spent, kids today are sorely short-changed by the educational offerings, and consequently, society is, too.

'tis strange I should be old and neither wise nor valiant. From "The Maid's Tragedy" by Beaumont & Fletcher