Not one of them knows how to gather food or hunt using what is already there. They pretty much eat foliage and the small amount of game they are able to catch until they die from exposure, eating poisonous undergrowth and falling victim to natural predators. It doesn't take much training or education to sweep a floor, buy something from the supermarket and come home and put it in the microwave. This is why new running, swimming and weightlifting records are made every year. Then there are our machines, which extend our physical abilities astronomically.
Most people do only what is needfull.
Most people are made fat, weak, slow and less durable by jobs that require little more than pushing a pencil or running machinery. Records are broken by very rare exceptional people whos vocation is usually the very sport whos records they are breaking. Hard work and tough living make for strong, durable and on the ball individuals. Easy work and easy living make for weakness. A hand is great, but put a sword in it to kill more effectively, and so on.