The value of cash "under the bed" declines according to the rate of inflation. That means that you need to have a way of holding that cash in some other form. You also need to have a way of accessing that cash as you need it. It is necessary to have a bank that allows an easy way to convert the held asset into cash as you need it. I use the share market to an extent to do that. Cash at the bank is never "worthless". It is the best and safest medium to use to transfer goods from a seller to a buyer. Imagine being paid in meat and veg when you sell your time. I've just had my lawn mown and paid $50 cash. I didn't ask him to take 2 mud crabs and a bream that I caught this morning instead.
Cas is not only convenient it is easy and well accepted. I didn't have "big brother" ask if the mowing was necessary or tell me who could do the work for me.
