Suddenly chatting with a friend today. How do blind people use mobile payment? We don’t know the daily life of blind people. Blind people pay with paper money, but will digital currencies replace paper money in the future? (However, there is no certain mark on the U.S. bills, and the blind cannot touch the face value of the legal currency)
I don't think government controlled digital currency will completely eradicate fiat money. At least not now! Also for the usability of blind people, features like Siri or Alexa will come handy where people can use payment system using their voice.
There are also some elderly and children who do not have mobile phones. Children can take care of them and learn cryptocurrency with their families. However, many elderly people have no children and lack the ability to accept new things. With the popularity of Bitcoin, will they continue to use paper money in the future?
As I have said earlier, I don't see fiat money disappearing anytime soon. Digital currencies will be rolled out to people who are interested in using it. So digital currency can coexist with fiat..