I left India in 1960. Last visit was in 1986. But I have a cousin who travels there often (he gets very cheap air travel as retired employee of United Airlines). He says India is 10 times more prosperous now compared to when we both left in 1960’s. It all changed when the big gov’t Congress party lost to the capitalist party of current prime minister Modi.
So why are so many Indians going to every prosperous country?
India is less than 1/3 size of United States, but has nearly 4 times bigger population. And India graduates more STEM students than United States. So too many people and not enough opportunities. Which is why you will find college educated Indians in UK, Germany, USA, Australia, Singapore, and dozens of other prosperous countries.
One advantage India has in a global economy is that its educated people learn in English. They may speak it with a heavy accent, but (and this is really pathetic) they generally read and write English better than your typical U.S.-born STEM graduate.