I doubt we will move to a cashless society any time soon at least not in my life time, and then once that happens you need to have a universal currency everyone can accept.. as a global community we can't even agree to cut emissions or try and move to greener fuels so add X years to that figure. The way I see it is crypto will never replace a currency system instead I think there will be more adaption for the block chain tech more than anything else, to trace where food comes from, parcel tracking, communication, storage that's the true value of the tech not £/$/€