To an extent, this is true. It is certainly possible for a kid with drive and intelligence to excel at any school. The issues more arise from the other variables - if your kid is attending a school in a low socioeconomic area, there is a decent chance that the cohort do not prioritise doing well in class. Suddenly kids not only find themselves among peers where studying is not a priority, they find themselves disincentivised to do well so they don’t stand out.

If instead your child attends a school where it is socially acceptable to study and do well in class among their peers, they do.