I think this fundamentally misunderstands paper wealth for real wealth, and financial capital for real capital, and you are getting away with it by pretending that wealth is like water -- e.g. there is a finite amount of it that people need to drink.
What is wrong with India -- and I understand this is not a fundamental explanation but a symptom of more fundamental causes -- is that it is difficult to invest and create more capital in the country. This has absolutely nothing to do with "hoarding" financial assets. What it means is that the credit/financial system is broken, so that if you have the skills and ideas and talent to do something you cannot have your plans priced by the credit markets. If there was a functioning credit market that would help enable productive ecosystems. It is, unfortunately not sufficient, you also need skilled labor that doesn't flee the nation, you need rule of law so that contracts are enforced, you need a stable regulatory environment so that investments can be planned ahead without paying bribes to various officials and interest groups, etc.
Absolutely none of this requires anyone who holds lots of financial assets to get off their as* and do anything at all. If they do nothing and don't invest, they will merely become relatively poorer as new entrepreneurs arise. They are not blocking the production of anything unless they use their wealth to actively create roadblocks (e.g. bribe officials to turn down permits for upstarts, etc). In an economy with functioning credit markets and productive eco-systems, it is not old wealth that innovates, it is new wealth. You still have Rockeffellers laying around but people like Elon Musk arise from the ranks of the middle classes to become wealthy on the backs of new ideas. The lack of Indian Elon Musks is not due to the Rockefellers "hoarding" their oil fortunes, anymore than middle class people like Henry Ford or Thomas Edison didn't get funded by old Timber barons. They got funded by credit markets.
So the problem with India is that while it has human capital, it lacks the other ingredients to create productive eco-systems that can create the capital needed to make India richer and more productive. So look to things like lack of rule of law, a bureaucracy that prevents new entrants, and a credit system that does not properly price new investment ideas. Rich people are merely passive holders of bonds or stocks and play no positive or negative roles in any of this.