Crypto gives banks the perfect opportunity to get rid of paper money though. They have wanted to get rid of it for year because tracking everyone's finances is their hobby.
Do you think banks want to get rid of paper fiats? Nope. Never gonna happen. Banks have ways to track your paper currencies as well.
There is only about 9% of printed money left in the worlds money supply, they have been moving digitally for decades.
Printing dollars and coins costs more every year because security measures for stopping counterfeiting have to be updated all the time.
The digital ledgers and distribution methods for money will be lower cost to update the technology, like updating your phones software. The paper fiat system currently requires thousands of bank employees to help remove money from the money supply when it's outdated?!?! Then they all add new money into the supply with better security, over and over.
There are more benefits to moving it all digital, very few benefits to continuing with paper money 20 years from now.
We will still have a "cash" system that banks can't track (decentralized crypto currencies) and there will be a digital cash system the banks and government use as a national currency same as we have now. This is part of the reason for all the media headlines about bitcoin fraud, crypto scams etc, the governments and banks don't really know how to move everything digitally, without having everyone move to the decentralized money.