Developing nations are already getting the benefit of much cheaper renewable energy. In 2019, 58% of the global solar panel market was delivered to developing nations. (That includes China). This alone is probably close to a $50 billion annual market.
But the major price drop which happened in late 2017 is just beginning to affect how the entire world views renewables. For the crabby Republicans who don’t want to see where their power plants are (although they don’t seem to mind seeing the filth from those power plants in their air) utility scale wind and solar is now cheap enough that they can afford offshore or to use renewable electricity to make transportable liquid or gas fuels. I just wrote another long answer explaining the whole thing, so I’ll link to it instead of repeating everything:
The New York Times reported a couple of months ago that the cheapest and most reliable way someone in war-torn Syria can operate a refrigerator and a cellphone charger is a $550 solar panel and battery array. I’ve known people doing similar things with renewables and high efficiency products for many years, but I don’t have good links to online information about them. The point is that if you have a grid, renewables are marginally cheaper than fossil or nuclear power. If you don’t have a grid though, renewables are affordable when the grid is not.
Developing nations universally have sunlight and wind. They don’t have fossil fuels or nuclear resources. They have the money to build incremental systems which solar is particularly good at providing. They don’t have the money to build multi-billion dollar monolithic power plants and the distribution and transmission infrastructure they require.
There are far too many ways this matters to list them all. Solar panels can pump water in places where nothing else works. They can power purification systems.
I also hope and expect that renewable construction and manufacturing will produce economic growth and jobs in developing nations in a way which cannot be done with fossil fuels.
Perhaps we ought to set up a Quora space for energy in developing nations. I’m not sure I’m the one to do it, but it would be a good topic. I would certainly follow it.