The problem is that renewables can be done by a lot smaller companies then fossil fuels. Solar can be done by a family on the roof rather easily. Wind turbines cost 3million per piece, so very possible investment for a farmer, small company and the like.

Fossil fuel power plants are a lot more expensive hence competition is smaller. We are easily talking 100million and more per plant. Large pipelines, refineries and oil or gas field developments easily cost over a billion. That keeps out competition. Not to mention oil having the largest cartel in the world backing it.