You’re talking about the supply chain collapsing, not about there being nothing to buy.
The supply chain is certainly something to worry about, especially for those in today’s cities relying on just-in-time delivery. Credit will certainly fail - for a time - so we who expect a crash should certainly have a deep larder, long prepared, at the very least.
But there have been many, many hyperinflations in history and the food doesn’t disappear. What happens is that fiat currency doesn’t buy it any more.
Ha!! I know not a great example...But I could envision food / soup lines..