Lol, it's the stupid mentality and pressure from relatives. There is a culture of people moving out of India because it used to be so much easy in the early 2000s to settle in the US and UK and also that a ton of Indians have settled in gulf countries. I can tell you that there are plenty of good job opportunities in India so that is not the reason to move out.
May have been true in the 90s or 2000s but not much anymore.
People mostly do it for the lifestyle these days and for the things which you can't buy - clean air, green surroundings, work life balance, public infrastructure, powerful passport, etc.
As for jobs, at least in my field, there are better (and better paid) jobs in India than in any Western country apart from the USA. Yet, there are things that money can't buy