Nothing can replace the paper money of the states. They are the crown of the creation of mankind over the past fifteen hundred years. They will not be easy to replace at all, and even more so cryptocurrency, which is not capable of it at all.
In the future, a cryptoalument will occupy the niche of one of the types of non-cash money, however, it will not be able to significantly affect the circulation of cash. Cash and cryptocurrency will continue to go together and complement each other's capabilities.