Learn history. Gold has been used as money for thousands of years.
Your interpretation of the Great Depression is incorrect but lets not go into this.
I am asking you why nobody is using gold (not gold standard!) as a media of exchange. (The answer is tax laws!, like bitcoin).
Because it is heavy, cumbersome, liable to tear and wear as well as counterfeiting and defacing. Actually, it is you who have to study history here. Silver coins were primarily used as a means of exchange, at least in Europe (don't know much about other countries), gold was stashed away as a store of value above anything else except jewelry...