The exact issue is that the school system is modeled after the one room schoolhouse. The entire concept of grades K-12 needs to be thrown out, and instead just have each student advance in each subject at his/her own pace.
I know people who went to one-room schoolhouses, and the learning was very individualized.
The kids who could handle the more advanced subjects got to them before they would have in the modern idiot factories. No kids were held back so that the 0.1% of them who might make a buck playing pro sports will be at maximum mass when they graduate college. No kids were promoted to satisfy social quotas and protect the NEA.
But most of it had to do with class size. Sure, the school had a 40:1 ratio in total students per teacher, but it got down to 8 or 9 to 1 (or was it 25 or 6 to 4) when you consider each subject. The kids not taking the given class were doing homework.
What must be got rid of is Big Ed and the NEA with their industrial-scale idiot factories.
It is a sad thing when most people are more willing to replace an old but working computer than they are to replace a clearly broken system.
Because if you dare talk about it you must hate teachers and children.