On public schools, supposedly Canada ranks higher than the US, but it is my opinion that my son's American public schooling is better than my Canadian public schooling. It is harder and more comprehensive.
When understanding the problems inner city schools in the US, people should watch The Wire in the season which focused on the Baltimore inner city schools.
On Universities, the best schools in the world are in the US, for the most part. However, some of the worst schools are as well. Many of these for-profit technical schools are a joke whereby people take on huge loans and are often unemployable when they get out.
Schooling reflects culture. America has wide societal disparities, so the schools will also. The average may be higher in other countries, but the best are in America, as are the worst.
Technical schools are important, though. Air conditioning and Heating, electrical repair, even cosmetology are areas that people can get jobs in.
My wife teaches cosmetology and loves to show that over double the number of students who graduate from her school find work in their field within 12 months than do those graduating from U.C. Riverside. (A local, high end University.)
Not everyone needs a bachelors. A lot of people with a bachelors in Liberal Arts or other underwater basket weaving majors are unemployable when they graduate.