Banks acting as governments get to do as they please, making up for their mistakes by simply printing more money. How do get away with it? Where does the "money" come from, the overprinting that is? From the people, from their purchasing power.

Once dollars were backed by gold. Now, this practice has been abandoned. Now everything runs on the governments goodwill. This is illusion. There is no control on printing money. It instigates inflation and inflation reduces the real value of hard earned money of common people.
Inflation is not bad if it remains within a limit because it is the sign of demand that results in expansion of businesses but when it crosses limits, it becomes a menace. Example of Zimbabwe, Venezuela etc are not far away.
Cryptocurrencies definitely can change this scenario. They have potential but a lot of efforts needed to make them replace fiats.