Solar generation has little economies of scale: PV arrays scale linearly, unlike turbines and electromechanical generators. Batteries also scale basically linearly; maybe you can have a better deal if you buy a truly massive amount of batteries, but I'm not certain it's so dramatic.

Transmission costs seem to dominate the price structure; I currently pay a generating company about $0.1 / kWh, and pay Con Ed $0.25 / kWh for transmission of that energy. And this is in dense New York City; in suburbia or countryside the transmission lines have to be much longer.

Centralized generation makes sense when the efficiency scales wildly non-linearly with size, like it does with nuclear reactors.