Lawmakers are sort of masterminds, especially when defining the founding principles of the law. They don't have pencil production, and usually any particular production, in mind.

The beauty is that a general principle allows almost any business to flourish; the lawmakers need not know what specific business it might be. This makes such laws reasonably future-proof.

I don’t think the author wanted to write a reference work on all aspects of its subject :-)

Here’s what I personally get out of its perspective: contentment and inspiration. It provides glory to the seemingly mundane tasks of everyday economic life. Comparing prices, finding customers and suppliers, solving small problems, settling disputes. This is what the invisible machine is composed of.

It also shields my mind, like a lode star that guides me away from many popular beliefs about what “needs to be done to boost GDP”.