And since 16- and 17-year olds are children, why should we not treat them as such?
I do not remember having been a child at that age. Indeed in no real-world sense is a 17-year-old a child.
Where I live the age of criminal responsibility is 16, at which point you can be tried like an adult. Yes, I would love to drop the age of maturity to 17 and 16, combined with voting rights, and I would also love to allow those
few individuals of extraordinary development who can be emancipated earlier (say, at 15) to prove their ability to do so in court (an extended version of modern emancipation).
So that I do not go crazy imagining what you might think the purpose of lower (elementary and secondary) education is, why don't you spell it out?
In my view the purpose of education is divided into two separate parts:
1. Imparting knowledge and skills making it possible for an individual to find a job and take care of themselves in the greater world, as well as become a functioning citizen. Whether these skills be historical knowledge, firearm safety, etc.
2. Imparting one's values (aka "raising them right"). This is the purview of every education system, even ones that claim to be value neutral. Hippie parents hope their unschooled kids will be little hippies like themselves. Fistful hopes his future kids will be good Christians, I do not doubt. I hope that my children will be like myself.
This is not to say all ideas are equal (obviously my ideas are the best!) but that we must learn to cope with the moral reality that every single other person thinks that their ideas are the best.
In the long run, 2 affects 1. If you believe part of being a good citizen is knowing history then 19th Century American history will be on your high school curriculum. If you think that society should evolve gradually from using automobiles to mass transit, perhaps driving won't be.
But as long as the school system is run by the state, the school system will continue being political. This is by definition:
the state is political. And then we are forced to contend with the fact that when I lose a political battle with fistful, fistful ends up setting up a dress code for my children. And when fistful loses a political battle with me, I end up choosing the content of his children's sex ed classes.
And half the time, these decisions will be made by an unelected 'education professional' appointed by a guy who was appointed by another guy back in 1983.
What education might look like in the MicroBalrog universe is an entirely different matter. But the chief things are that it would be overwhelmingly private, and with far more choice for everyone involved.
And if - if ! – we are to have public education, it should not work the way it does today.