That should lead to inflation, which results in the decline of paper money as an asset. (thecollegeinvestor.com)
They're also an easy substitute for paper money in worst - case scenarios since they come in a variety of weights and denominations. (hardassetsalliance.com)
Credit is still a fairly new concept within the history of finance, so many people would rather stick with paper money than charge purchases to credit cards. (gobankingrates.com)