I read that Goldman sachs and Bank of America are now getting into block chain /cryptocurrencies.
Primarily for tracking purposes. It’s easier to track than traditional money.
Secondly they do not want currencies like bitcoin to get too powerful because it risks transcending the current banking system currency.
Gold like Bitcoin is all mainly based public perception. Yes Gold has been the traditional go to backing of money, but really since about 1971 when President Nixon took us off the gold standard. It all changed and became based on the market perception.
The eroding paper money is also public perception.