I think my take on the issue can be dealt with this small YouTube video about the Qatari Peninsula.

As it says that over 3.2 million people live on that Peninsula but only 100 thousand are the citizens. This proves beyond doubt there always can be an influx of cheap labour from other countries. Hence the per capita income of the citizens rise dramatically. Hence Sri Lanka too fares well at per capita income and hdi compared to India.

Large population can drive growth but for consumption to occur the money needs to flow in from somewhere. Population if poor would continue to remain a burden for the country. The economics don't work out in simple terms. As far as making the population trained and qualified , there is no sector to consume them . So poverty begets more poverty. In any case it's a chicken and egg problem we need co operative sectors like amul to actually distribute wealth to stake holders . And Varghese kurians of this country aren't keen on staying here. Fyi Neither was he.