And how do you get parents to universally improve over time? You can’t drive the improvement without a top down incentive at bare minimum. If no child left behind failed, look at why and try again, don’t give up and say the nation will be illiterate outside of the ruling class.
I even remember in econ101 my professor brought up the basic analysis, then brought up a really cool example of this where the minimum wage changed in one state but not another in two towns right on the border. It was the perfect econ experiment to prove how supply and demand would cause inflation.
The next 5 years saw no change despite a 2 dollar an hour increase on one side only - the two towns maintained equal pricing, and no increase to inflation or pricing compared to the typical rate.
My favorite part was that he managed to be excited about it properly, because it was and is cool science to him when usually economics is trying to analyze how changes happened with way too many variables.
So the only people who have say over the life of a child is the parents. Children have no personal rights against domestic abuse including neglect. In this specific example, neglecting their development.
The nation has a responsibility to make sure that neglect by the parents does not mean abuse to the child. That’s why the ultimate solution for neglect is foster care. In the same sense, the state can encourage involvement by parents, but can’t rely on it. Orphans exist, and more directly, abusive or neglectful parents exist.