By 1915 America had higher GDP per capita than most of Western Europe - BEFORE WW1. Western Europe had higher GDP per capita than China/India by like 1200 AD. You are so so far off the mark.
Also, India's population only started exponentially growing in the late 1800s. By that point America had already industralized and was already the richest.
Go ahead and put your money where you mouth is, sell all of your US stock, and invest in African stocks since population growth is apparently the only thing that matters.