Unfortunately, in general, you are correct about the lack of any real teaching. There are some exceptions. In the few instances where you find some good teachers (and a supportive administration) you discover that inner city students actually respond well to a challenging curriculum. When things are too easy, it’s boring and creates a climate ripe for behavior problems.
But then when the students get too smart, they’re accused of “acting white”. Also, when the inner city students see schoolwork that’s too challenging, they start complaining and they throw fits instead of trying to learn how to do the work. They’re really not used to hard work.