Your topic is very wrong. People who hold money may not hold it in their bank account. Most of them are business oriented persons. So the money they have at hand is used to do daily business some also give out loans to people with the money they hold. The truth is, its not all about holding money at hand or at the bank but what matters the most is what they do with the money they hold if they keep on multiplying it to get more.
This morden age one don't need holding a fist currency, we can save them as emergency funds and also invest in crypto currency if we want to become wealthy and successful in the future. Fiat currency lose value everyday and holding it will neither do one any good. Imo shitcoins and fiat are like one. Suggesting to invest in Bitcoin for the long term so can make a good profit within 2 circles of Bitcoin.
There are other forms of investment if we choose to invest our fiat. Aside cryptocurrency there is real estate, human management, and so many others. I noticed people choose cryptocurrency as a preferred choice of investment while eliminating other opportunities that may come for them in life.