China's IQ is often cited as being 104, though in reality it drops to around 95 away from wealthy coastal cities.

Indian IQ estimates vary wildly from Lynn's 76 to 110 according to studies on wealthy students cherry picked on reddit. I can't find any studies on the general adult population besides Lynn, however most sources accept Lynn. It is safe to assume, walking through a typical street in Delhi you are not among an IQ 110 group like American WASPs, it is probably closer to 76 and lower than China's.

https://timesofindia.indiatimes.com/etimes/trending/this-country-has-people-with-the-highest-iq-check-the-position-of-indians/articleshow/118386797.cms

This is definitely a major factor, further amplified by capitalism where being slightly more intelligent and slightly more effective than competitors will see you capture most of the market share, and capital markets blow up figures further.