What really powered the world economy for a hundred years was petroleum. Eventually, there WILL be peak oil. One can debate whether the peak will be in 10 years, 20 years, or 50 years. But it will happen.
Simply put, in terms of energy density, applications (transportation, power, fertilizer, pharmaceuticals, asphalt, etc), portability and scalability (cars, motorcycles, power plants), petroleum is unrivaled. Not nuclear (Fukishima, Chernobyl anyone?), not solar (EROI anyone?).
We aren’t going to find magical dilithium crystals to power everything, because they don’t exist, anymore than leprechauns riding unicorns that poop rainbows into pots of gold exist.
America produces so much food, because it MANUFACTURES food by pumping massive amounts of fossil fuel products into the soil. Factor in the illegal immigrants picking fruit, the people making fertilizer, the trucks transporting food, etc, it is a lot more than half a percent working in agriculture.
It is like saying the Earth’s space programs have only has employed a few hundred astronauts.
Parson Malthus was wrong.