"I can't imagine that there would ever be an enforceable obligation to contribute toward the education of the rising generation via private, schurch or home schools (the essence of "private, church, home" is that it IS private and voluntary.)
But as I said, the fact that parents are paying all the costs of a workable future society, and your generation would reap an ensemble of tangible and intangible benefits, ought to inspire some thoughts of inter-generational solidarity.
Solidarity. That's a good word in anybody's vocabulary.
We are on the same page WRT the public school system, but my point remains. The money spent on today's children are not an "investment" by the working population of today. To make that point valid we would have to be expected to not compensate for the services/products that those children will provide when they are of age.
Anyone getting an education is making an investment in themselves and hoping to increase their future value. I will compensate a doctor more for their services than I will compensate a bartender. That is true regardless of my age. If the family does not teach their child that education is important, then their potential value is cheapened.
The "society invests in children" side of this argument is only denying that they are responsible for ensuring that their children know how to maximize their future value. This argument actually is worse for our future than the individualists expecting to fairly compensate a service provider in the future.