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.
Of the three Gold & Silver or using Cryptocurrency, the latter is the best option, it is the most sought and with high potential assets eight now, I agree that as long as the internet is existing we will have Cryptocurrency it's now part of our modern way of life, it's gives us equality whether we are living in a first world country or a third world, but I highly recommend that you not put all your eggs in one basket, you must also include gold silver must put more on Cryptocurrency.