I was listening to "The Rational Optimist" which concentrates on the benefits man has achieved by specialization and bartering. In short, he argues ALL benefits we've achieved have been by specialization and barter. He even says this is the biggest difference between man and animal. Markets and government just help orchestrate it. Certainly if I had to do all the diverse work to provide for my own needs, I certainly would think and live about like the ape I am. But I had noticed before the key to production is the isolation of inputs, orienting them and placing them close for attachment to another input and usually using a tool for attachment. Or a tool for working on well place inputs, or working on them in stages in a certain way. But a key is that there should be only few different types of inputs compared to all your life's needs, and that you be geographically located to a concentrated source of those inputs, or someone can cheaply transport it to you. So it is not only energy that we've made use of in society, but a fantastic source of low entropy caused by the pre-existing placement of Earth's materials. Imagine the difficulty of production if the Earth's crust and biosphere were homogeneous. So we ARE using up low entropy as we change the crust, just not in a way he mentioned. We can't get it back except by using more energy or waiting for geological processes.
Specializing in a skill is creating a tool that is good at the manufacture of the item.
Agriculture, especially monoculture, is a way of reducing the entropy of what we have to gather.