Life is rather uncertain nowadays as anything can happen at any time and we would be caught off guard. Thats also one way to describe the current economy at this stage. With the worlds economy expanding and expanding there have been more crashes as the years go by and they are becoming more frequent and some say at any moment one could happen.
So you are left with a situation in which the money you currently own, fiat money: the dollar bills & coins, will become worthless and you cannot even buy anything you need to survive on a day to day basis. In this situation, people will have to resort to a system of bartering like in the stone ages. I guess if you have a lot of stuff with value you can trade that would be great, but a majority of people dont have such a stash. Things can get ugly real fast.
Therefore, in such a doomsday situation you have to come up with a situation in which you can trade with people in order to survive. There are two solutions I can come up with, either using precious metals such as Gold & Silver or using Cryptocurrency. Considering that fiat currency is useless, Cryptocurrency might raise in value so that it can be useful as a means of trade as long as the Internet still exists which will most likely be the case.
There is an economic crisis that is sighted on horizon. When it comes, fiat currencies will have big difficulties. People will start a search for alternatives to fiat currencies. Then, more people will discover cryptos and especially Bitcoin. And the demand for Bitcoin will start to increase very fast.
While the demand for bitcoin at that point will increase significantly the real action will happen on the supply side of the equation, what are going to do all of those people that are holding bitcoin? Many speculate that they will sell their coins but I cannot see the point of that, why would you get out of a coin that everyone wants and get a coin that no one wants, most likely what will happen is that those that are holding bitcoin will keep holding it and will only exchange it for stuff of real value.