No, a “medium of exchange” is one attribute, but not the only, of money. It must be a store of value as well. Clearly, the trend for collectivists is to destroy, or at least control these attributes. Some have argued for money to have an expiration date, in order to force spending? In any case if “money” does not maintain value it will eventually be refused, no way around that.
While gold may well be archaic, it is useful to understand it, and why it became money - indestructible, scarce, divisible, homogenous, fungible,recognizeable, etc. The problem today is there isn’t really an objective or standard unit of account. There are standards for distance, time, or weights and measures, but an elastic currency distorts things over time and governments cannot resist debasing whatever is used as money for their own benefit.