You can say "cash is trash" and "Bitcoin is the king" 100 times
Cash is trash used by the OP was a statement made by Ray Diallo acouple of years back, always check OP message next time before making conclusion.
With that been said, if we do some research about the inflation level of fiat currency during the total lockdown season we can say cash is trash while bitcoin is king cause it maintain a stable price.
But when you go for shopping, you have to pay with fiat, you get salaries in bucks. So maybe cash is trash, but it's irreplaceable "trash" now.
Some store, mall, nerchant now BTC and people even received their salaries in crypto in the countries where bitcoin is legal and supported by the government.
Meanwhile, you shouldnt expect something create in the year 2019 to overthrow something that was to be used globally since the year 1971