IIRC it was Tesla who developed AC transmission, Westinghouse that incorporated it, then put it to wide scale use, and Edison who fought it tooth and nail before dropping DC and swamping the competition in the market. AC is precisely what created commercial applications of electricity.
I’m referring to the method used to gather power. I single led light is useful to keep a dark hallway lit enough at night to sort of see where you are going, but’s not going to be enough to cook you your supper or power a television. In that sense, it’s pretty useless.