wait-- do you have historical evidence that "money" replaced "direct trading" at any point in time? Why do you pick "end of middle age"

suggest reading Debt: the first 5000 years.

Never mind history. There is no evidence of "money" replacing "direct trading" today, so there would be no need to go back in time. But obviously it wasn't meant to be taken so literally. The "between the lines" intent is understood.