It’s hard to compare apples-to-apples, though, since the capital efficiency, payback period, and profit pattern are so different. If you have access to limitless, relatively cheap debt, then yeah, there’s absolutely no reason to build fossil fuel plants anymore. Developing countries don’t have that luxury, and even to the extent that they do have borrowing capacity, they may have even higher-IRR things to use that capital for.

Not saying any of that is true of India specifically - I’m not familiar enough to have an informed opinion there.