Let me go to the point trading has to do with either physical market or online marketing also know as digital marketing. On digital marketing trader are likely to use cryptocurrency which can be .
When was bitcoin used for digital marketing? Or since when do people spend their bitcoins just like dollars?
The percentage of bitcoin acceptance in large stores and popular shopping sites is small, and some resort to indirect ways to buy with bitcoins, and therefore bitcoin is not the number one currency in digital marketing.
Existing variants can only differ by adoption and further adoption.
Gold
How can gold be used to buy something digital or even something real without going through paper money? Even the settlement of transactions, even if they were done with gold, is done with the value of paper money and not with the weights of gold.