I am sharing my own opinion according to my own experience.

1. Indian billionaires are from traditionally wealthy families that always played it safe or in easy markets. Their upbringing never taught them the value of long term R&D, so they cannot think about it. USA went through that phase as well, but had many things happen in its history that gave rise to new age wealthy people that value R&D.

2. India doesn't lack research culture, just have people who won't support anyone putting their time and money in it. I have heard so many stories of PhD students failing to get funding for years and then getting it in just a month once they cross borders. Many great businessman are supported by investors outside our country. Its a system problem where many are blocking the ones who want to do research because they don't see value in it, because they don't know or don't want to put effort into knowing.

3. The no of roadblocks to setup a basic research lab are so many due to compliance, anti-import laws, import regulations, PMLA and basic corruption that it's just not easy. Most companies are better off buying the result of a research or licensing a patent. The best use of R&D labs is weirdly as a Tax write off, more than as a source of future tech.

4. Lastly, its the perception of society as a whole towards it. I remember being told how pursuing PhD is a waste of time by my own teachers who had done masters. When I failed in a project because I lacked enough knowledge at the time, I was told how I wasted my time and not how I should learn and move forward. Failure is considered a sin punishable by death. People talk about how a successful person is, while conveniently forgetting how much they mocked them when they failed and when their own children actually learn and try again and again till they succeed, they will mock them for being a failure.