Can't eat it, can't shoot it, don't want it.
Unless you live on several acres and have the wherewithal to raise every bit of food you have, mine powder and primer chemical components to make powder and primer, mine and process lead, copper, and brass into completed rounds of ammo, you will need some unit of exchange to get said food and ammo.
The existing counterfeit Fed notes work for that right now, but the scam will wind up very quickly and without warning. At that point, some sort of new worthless fiat currency will take its place, and it will not hold value to any extent.
Gold and silver can be used under those circumstances, and you can barter, too. Crypto currency is another store of value to have in addition to precious metals and barter items. You don't want to put all of your eggs in one basket.
Also, TEOTWAWKI is not the only thing to prepare for. There will be plenty of purely financial calamities involving the currency, and you need to prepare a portfolio of alternatives to Fed funny money. You will need something to exchange for the food and ammo.
Let's see....cryptocurrency that only exists online.
Chinese and Russian state backed hackers.
Seems a great idea, what could go wrong.
https://markets.businessinsider.com...llion-but-the-money-is-gone-2019-3-1028009684
The block-chain technology is designed so that the code has to be validated by the thousands of computers in the decentralized network. If one person tried to hack anything, it would result in that hacked entry not being accepted by the rest of the network. This isn't like your bank account. Also, you can store your crypto on a hardware device, which is sort of like a thumb drive. No one is hacking that.