I don't think the miners can not exactly decentralize the energy grid but they have definitely helped grow the grid on many occasions, some of which were actually very positive. For example a couple of years ago I read something about our government working with the miners to work on infrastructure to use the Gas Flare (wasted gas produced during gas and oil extraction) to generate electricity. Something that led to establishing massive projects to catch and use a whopping 20 million cubic meter flare gas (700 million cubic feet) on a daily basis.