Digital money can never replace fiat or credit cards. It will be not possible in the counties where the Internet is not used or used only by a low percentage of rich people.
Cash, money in the end is numbers. As long as you get what you pay for and work for and your account balance has the right numbers, there is no need for cash.
As long as you are and have access to your bank you may think so, but the moment they decide that you should for one reason or another be considered a criminal or "an enemy of the state" and lock you out from your funds, you might want to reconsider. Actually you might come to the conclusion that cash is the best think ever.