I raised my kids in the Mira Mesa area of San Diego. The Asian community is a significant percentage. There is a culture of sitting at the kitchen table and finishing homework each day after school. The net result is very high academic achievement. I'm not Asian, but my sons benefited from those same cultural practices. My middle son finished with a 4.33 GPA and scores of 5 on his AP exams. A good example was set and followed. There is no free lunch just by virtue of breathing the same air in the classroom. The benefit was sharing the common value that regular effort to excel academically pays off.
I must admit there was some homeschooling. I corrected all the math, English and science papers because the public school teachers failed horribly in that regard. I spent time teaching math and physics skills to my sons that weren't happening in the public school classroom. My middle son embarked upon fluency in Spanish. His fluency is good enough to represent real estate clients in legal proceedings to help them understand and communicate their needs and responsibilities.
When parents say that their children are in a good school district it almost always means that the parents are doing a ton of afterschooling, private tutoring, or study clubs. The parents and kids do all the work outside of school and the school is quick to claim the credit.
Of course, if the kids aren't getting tons of afterschooling their standardized test scores show it and the school blames the parent.
Gee! Win win for the schools. Good standardized test scores: School takes credit. Bad standardized test scores. Blame the parent.