Henri Lefebvre's theory in 'The Production of Space' states that capitalism would have failed after the Industrial revolution if not for real estate. It is the value of land/space in cities that sustains capitalism and stores 'surplus value' of capital. 'Money' or 'exchange value' liquefies real estate value. David Harvey also uses Lefebvre's ideas in many of his works. Suggest checking out these 'Marxist' philosophers. Of course, this is the exact opposite theory to the one in this article.

The role of 'money' is just to provide liquidity to capital. Surplus value needs exchange value because capital if stagnant loses its value. The role of debt is to assign exchange value to real estate as a means of storing capital.

My theory is that Marxism is outdated. The world is not structured around 'Capitalism' or even 'money', but rather 'Production'. Capitalism and money facilitate production, but it is production that is the main organizational structure of society.