Decentralised power generation and manufacturing is horribly inefficient. In general, ten small engines is going to be less efficient than 1 large engine, becau

Decentralised power generation and manufacturing is horribly inefficient. In general, ten small engines is going to be less efficient than 1 large engine, because of the constant overhead costs that each device incurs. Not sure about agriculture, but I suspect the same thing applies: if we gave everyone a small farm each, overall you'd wind up with more land usage producing less food.