AKA: why are 99% of AP classes Asian/Indian
You might want to ask in a less serious sub like askreddit or even trueaskreddit.
You're experiencing a confirmation bias. The Asians you're seeing are generally from already educated families that are at least middle class. I don't think you're taking into account the millions of Asians that don't have proper education or are impoverished.
Educational performance is a direct result of economic stability.