SOME public schools are failing.
Others are doing superb jobs.
Statistically speaking, the wealthier the community students are drawn from, the more likely the kids are to get a superior education.
There are exceptions, of couse, but that's, generally speaking, the way it is in America.
And that's NOT all just because of the money invested in their edcuations, either. (although it certainly can't be entire ignored)
The fact is if you go to a school where the average kid is poor, even if you are a motivated student, it can be very difficult to get a decent education.
The staff are busy dealing with kids who don't care, and often the educators are simply weary of being turned into prison guards and nursemaids, and not longer really able to teach in that environment.
They develop the educator's equivalent of compassion fatigue, I think.
When I taught I used to throw disruptive kids out of class just to make it possible for my kids who were interested to carry on.
Eventually, of course, the administration forced me to stop that editecian triage system of educating, and then the whole damned class could be totally disrupted by one genuine asshole or the other.