What is missing is how spending is funded. Consumption cannot precede production. Robinson Crusoe could not just “spend” and realize greater wealth. Were people to simply consume and spend without producing and/or saving, it would just consume preexisting production and/or savings. This would not lead to stable economic growth. What enables true economic growth is production, saving, and capital investment. Imagine an economy that had to be rebuilt after mass destruction of capital and consumer goods. The solution would not just be to spend, but to produce and save, then to channel savings into capital goods. On this, Richard von Strigl wrote:

Let us assume that in some country production must be completely rebuilt. The only factors of production available to the population besides laborers are those factors of production provided by nature. Now, if production is to be carried out by a roundabout method, let us assume of one year’s duration, then it is self-evident that production can only begin if, in addition to these originary factors of production, a subsistence fund is available to the population which will secure their nourishment and any other needs.

The introduction of money into the equation does not alter the essence of funding. Money is and economic good and acts as a medium of exchange. It is only employed to facilitate the exchange of goods; money cannot replace the consumer goods. The demand for goods is not constrained by increases in money supply, but by the production of goods. According to Rothbard,

Money, per se, cannot be consumed and cannot be used directly as a producers’ good in the productive process. Money per se is therefore unproductive; it is dead stock and produces nothing. …

The government is not a wealth-generator and the central bank’s monetary policy involves the exchange of nothing for something. These activities undermine economic growth, they do not create or encourage it.