Is there an absolute standard of monetary or economic value? Nope. The monetary universe is not Newtonian, with a fixed frame of reference, but Einsteinian, with frames of reference moving with respect to each other. Prices are exchange rates with no substantive existence.
As the monetary economist Hans F. Sennholz instructively wrote:
There is no absolute monetary stability, never has been, never can be. Economic life is a process of perpetual change. People continually choose between alternatives, attaching ever-changing values to economic goods… [T]he exchange ratios of their goods are forever adjusting…nothing is fixed.
Money…is subject to man’s valuations and actions in the same way that all other economic goods are. Its subjective, as well as objective, exchange values continually fluctuate. … There is no true stability of money, whether it is fiat or commodity money. There is no fixed point or relationship in economic exchange…[in] this inherent instability of economic value.– Hans F. Sennholz, Money and Freedom (1985), p 37.
As part of all this, governments and central banks can depreciate the currencies they control, run down the purchasing power of wages and savings and, in extreme but repeated cases, create hyperinflations.
There can be better or worse, but no perfect monetary system. All of them—whether the gold standard, gold and silver, a gold exchange system, the Bretton-Woods system, pure fiat currencies, independent or dependent central banks, inflation targets or not, fixed or managed or floating exchange rates—have various combinations of problems and advantages, and chances of breaking down.
Reality is so difficult.