A 100% competitive free market is the analogue to a frictionless vacuum in physics. It's a convenient model for academic purposes, but it's not something that really exists.

There is no such thing as a free market. A free market is a spherical cow in a vacuum. Corporations are generally far more informed of the nature of labor markets than labor itself a don't risk an equivalent of getting a life-threatening condition while having no health care. Corporations also collude, whether directly or indirectly, in many fronts.

And yet the theories of the free market, like many physical models, retain significant predictive power!

In the grand scheme of things, in long-term timeframes, with huge error bars. Those error bars are big enough and the timeframes weird enough that it's not sufficiently useful even for entire industries over very human timeframes.

It's incredibly useful. Open up The Wall Street Journal and look at oil futures or go for a drive and look at the price of gasoline. Watch a demand shock (like a pandemic) drive the price down. Watch a supply shock (war with Russia) drive it up. Or go over to the Federal Reserve website and look at the size of the money supply and how it's growing, and then go to the store and see this drive inflation, or go on vacation and do some foreign exchange.

Amazingly, fantastically useful.

And yet totally insufficient to describe many things that happen in markets, insufficient to explain the nature of economic crises, weirdness in niche markets of all sorts, the behavior of money, and a long list of etceteras that continue to baffle experts that have dedicated their entire lives to it.

Does a free market exist anywhere on Earth?