The point being if economy goes to shit that beautiful $100 bill you can spend to feed your family with lobsters will be worth as much and only as much as the paper it was printed on (hint - close to zero). In such times we will revert back to hard currency - gold and coins. But don’t buy gold bullion - it will be hard to buy bread with a 15gr gold bullion bar and noone will care to give you change. Hence best are 80% silver bags as a form of daily purchasing power.