Money isn’t a made up concept. It’s a stand in commodity, a universal exchange commodity. It represents the exchange value of socially useful labor.

Money is fetishized and treated like a think in itself. You’re not buying made up things with it. You “buy” money with labor and purchase the products of other people’s labor. You can print all the money you want but it doesn’t expand the sum of national useful social labor. If the money newly printed remains in circulation it will simply water down the exchange value represented per unit. You can print money but you can’t print tangible commodities; you can’t print bread, oil, houses, electricity.

Your premise is a lazy cope out. Social constructs are mutually agreed upon, but without a material basis then there would be no purpose: no material consequence.

The belief that money is imaginary harms the working people directly responsible for the creation of social value, while benefiting the wealthiest members of society whose business is the extraction of social value from the working people. It totally alienates the worker from their role. They believe that they are being paid by the capitalist in imaginary figures something that belongs to the capitalist. In reality the value represented by the money they are paid as well of the money they weren’t paid was born from them, by their labor.