I would not miss cash, I am more likely a digital orientated person. But yes, cryptocurrencies would take out control of the hand of governments, which surely they would not support.
I will not have this choice as I am working with the cryptocurrencies but I will not have to refuse from traditional money. I think the mankind will always use both of this money forms. I will not do it either.
I think most crypto users are like that. Fiat and Bitcoin will never be separated, because both things support each other. well, basically the development of bitcoin is also based on the support of people who use fiat.