I think that after that black money crackdown with the Prime Minister of India taking out the 1000 and 500 rupee notes the economy of India was in pretty deep trouble. But now the situation although isn't a lot better has at least improved a bit which is probably why the stock market has hit 30k+. There is a lot of renewed optimism in my opinion, even though they had to wait a long while for the cash to arrive.

It's projected that India will exceed China in population in a few decades, meaning that even if it isn't a superpower it will have the world's largest labour force. As Jherek above me said, it'll really be a tough job for China to catch up to India once the Indian population exceeds China's.