I'm not so certain. I've been in many educational environments ranging from home school to private college prep high school, to suburban high school, to inner city high school, to the ghetto school in the area.

There were good and bad teachers in all of those. However, the good teachers may as well have not had existed in the inner city/ghetto schools. Their talents were 100% wasted, and those classrooms would have been far better served with a police officer in front of the classroom who was enabled to boot the dysfunctional future criminals from the classroom. With those students in class, there was no point in even calling it school. Call it daycare, or juvie, or whatever you like - learning wasn't much of the process though.

I find it hard to blame teachers when their job is primarily daycare, and they have zero tools available to them to deal with poorly performing and disruptive students who have no business being in the classroom.

tldr; Almost all the US education problems can directly be tied back to the parents. Full stop.

This goes for my private schooling as well. The college prep school I went to was probably more diverse than the inner city school - the only difference was the self-selection of the students and parents who attended. They also taught with about half the funds.

That said, there are tons of horrible teachers too. The problems go far deeper though, and until you solve the parenting problem you may as well shut the public school system down in many areas. No amount of epic-level teachers will be able to get anything done in those environments.