Then how do you explain even more widespread failure and apathy in those nations where education ISN'T mandatory?
Give me some specific examples.
Interestng you would cede the right to parents to cripple their kids' lives (granted, many are doing a pretty good job of that already). In Barakistan then, are we to have NO child welfare laws?
In Barakistan, laws would be private phenomena, not government decrees. The answer to the question of what's against the law would depend heavily on context.
Can folks make like a bunch of them notorious Iranians and marry their daughters off at age nine? Bind their feet like old-time Chinese? Have 'em go work six days a week at the Nike factory? Sell 'em into the sex trade?
Probably not near the sorts of places you or I would live, no.
But you'd have a tough time, I think, convincing a private judge that you had the right to forcibly confine somebody else's kid for several hours a day against his or the kid's will for a period of twelve years or so.