Naive question here: I've wondered about this. Non-parent here (so far), so I'm about to arrogantly over-simplify a lot of things...
The science around teenagers needing more sleep, and doing better in life/school/everything if they start their day later, seems well-established at this point.
Additionally, there's plenty of known-better ways to learn beyond the rote-memorization-and-standardized-test system that's still de rigueur.
Are there no schools out there that put these things together and make an attempt at something better, especially for high-performing kids? What if school started at (say) 10-ish, and it gradually became more and more self-directed as kids headed towards graduation? What if it also mixed in all the latest cutting-edge research about how kids learn math/science/languages/etc? What if it also got creative with the curriculum and mixed in all the topics that people always say should be in schools, like "how to do your taxes" and whatnot?
I remember getting to college and being wildly unprepared for everything. School before then was devastatingly boring and fostered very little independence. Then college came along, and it was both brutally difficult and had almost no guardrails of any kind.
It was quite a transition, and it makes me wonder why there aren't more varieties/experiments around radically different approaches to schooling. At minimum, for high-performing kids, you'd think the modern world would have something.