You don't have enough basis for calling flat will fail and will implode eventually. It may look to you that cryptocurrency is the futuristic one but the problem with that is there is no guaranteeing its price other than demand and limilted supply. Government could make their own blockchain technology to engage in transactions but not removing the usual flat we know. They can make a crediting system where in it uses both cryptocurrency for online and flat currency for offline transactions which I think the safest thing to tell right now because I see it in my country.