No economic theory that based its findings on conditions prior to '34 has any validity in today's economic reality. That takes in a lot of economists who were trained in those theories as well. Their thoughts, unless they totally revamped them to conform with chartalism and "state created fiat money", begin with falsehoods that make them useless. No amount of charts and formulas can make a lie into the truth.
When FDR suspended the gold standard in '34 the dynamics of economics changed totally and forever. Instead of dealing with limited supplies of currency and unlimited resources, the world, due to America's dominance, suddenly found it had an infinite supply of whatever it decided to call money and considerably more limited resources to deploy with that currency.
The major change made by this move was making the currency issuing government the determining player in the economy, controlling demand and velocity of exchange as it determined best for the parties it represents. It, with both fiscal and monetary policy in its control, could shape the economy however it wished and for whoever's benefit it wished. It is hardly surprising that the moneyed interests of bankers and oligarchs would throw everything they needed to into preventing the average Joe citizen from realizing that such a change had taken place.
It was, and is, imperative to their fortunes that Joe citizen keeps thinking of economics in terms relative to his household budget and never realizes that his government is the "source" of the dollars he gets paid in, not a "cost" in dollars forcefully removed from his pay. If he does, and translates that into his political voting preference, it's game over for the oligarchy that has leeched off of his labor all of his life.