People will want a standardized token of value that is universally accepted.
why? this is not how commerce was done for most of human history. to get to a single fungible token, whether it has inherent value (ie a system in which cash is rare and the system itself unstable) or it represents debt (historically more common and stable), we have to presuppose a state whereby one class exerts it’s dominance over another class because both the issuance of currency and the tax must be tightly controlled. but the extant state in our hypothetical is the dictatorship of the proletariat, after class divisions have been erased.