The idea of public schools as a way to enforce national unity (~WW1 when it became a priority in the US to de-italicize ethnic identities and loyalties) and teach kids skills that would set them up for nationally important jobs like those in science and technology (Cold War) was a much later phenomenon.
It has fallen behind though because the folks in charge have lost this as a goal and there are so many out there with expensive useless degrees who have trouble navigating the world.
If someone were instead to home-school their children, and use that as an opportunity to show their children different systems in different parts of their country or world, I think that would be far more effective.
https://www.mrctv.org/blog/not-single-student-proficient-mat...