TLDR, it's the lowest common denominator students and teachers that make public schools inadequate for good schooling for brilliant students.
I think many/most states do curriculum locally, and if not then it's state. That just tells them what subjects they have to teach, though, and that is usually Shakespeare vs maya angelo. Not often does it mean algebra vs george floyd. The fact that they can be all over the place on literature and history is largely meaningless as the industrial/tech/defense status of the nation doesn't care if you read Hoppe or not.
What will screw up your classroom and stop your genius student from achieving is the fact that he isn't segregated from the other students who are dumb. There are small efforts here and there, and sometimes you can get a real different outcome, but mostly it's nothing different.
I was in gifted classes from 5th grade on, in about 5 or so different schools. The other kids in my classes were not geniuses. Maybe one or two. Mostly it was just upper midwit tier students. The ones left behind in normal classes were below midwit, but not fully retarded. They struggled with basic material. These are all 90%+ White schools I'm talking about. Some of them in very wealthy places where the parents are doctors, lawyers, and pilots. There was no real class for really really genius students. You had to go to private school for that. The "gifted classes" moved at the same pace as the regular class, you just did more work. The pace of the regular class is set so that most of the mouth breathers can keep up. It is slow as pond water. A genius kid could do the year in a month if he wasn't being held back.
The biggest problem with public schools not being good enough to consistently output brilliant grads is that the brilliant students are shacked with all the others, and every sociopolitical norm says you are playing with fire by trying to separate them. What are you some kind of nazi? Every retarded nigger can be a rocket surgeon. It's just socioeconomic factors, biggot.
Teachers is easy. Education majors in college (future teachers) have pretty much always had the lowest standardized test scores of every college major. Maybe they go up one slot now and then, but they are consistently the dumbest group, so the White Rhino smart teacher isn't moving the needle at all. The genius kid in public school has a retard for a teacher, by comparison. He needs a genius teacher, and geniuses don't become public school teachers. The genius kid likely has another genius somewhere in his family, like maybe his dad, and 100 years ago that would have been his teacher.
