I don't think money will disappear. "Necessities" in many countries are practically free - which of course depends on how you define necessities. People will always find ways to accumulate wealth to pay for what they want more. Star Trek made a wooden attempt in "The Next Generation " trying to convince us that money was no longer needed in their time, but then it spent many more years showing us that trade and money were still desirable. I agree that Bitcoin might fade but usefulness, but many currencies have gone by the wayside before.