Well, I think Friedman's description was more complicated than that, and probably not really a good example. Many people know how to make pencils, although they might not know every detail of everything.

Still, to know, one really only need read Henry Petroski's delightful book:
The Pencil: A History of Design and Circumstance

Petroski is a fine writer of many engineering books, in this case, detailing the history and manufacture of a simple-seeming item we take for granted.

I doubt that any one person knows how the whole of our system operates.

Indeed, that is an advantage, and why the capitalist system is "successful". Distributed or network decision making allows more complexity than could be directed by a smaller group of individuals. I am just reading a book on the history of the Industrial Revolution, and the breakdown of the rigid hierarchy of guilds after the middles ages is what laid the foundation for the Industrial Revolution.

Network systems tend to have emergent properties which are hard to predict, unlike hierarchical systems where those in charge can dictate the shape of events. While some of these unexpected properties are beneficial, some will not be, and will then be hard to "fix" because there is no single point where the decisions are made.

Politicians are really now just observers of the system, but give the illusion that someone is "in control". It's a bit like the illusion that your consciousness controls the actions of your mind.