At a time where I see currencies moving away from cash to digital I think the reason is partly so that governments can control the flow of their currency more particularly for laundering. They can possibly gain more taxation from a cashless currency because cash cannot be fully traced. If i sell my car for cash to another individual the government dont get any revenue from that because it is not traceable.
So in a governments aim to control our money it will leave a big opening for bitcoin and other decentralised crypto to exist along with fiat and will allow people to "trade" anonymously with each other over a completely independent infrastructure.
Im just starting to notice that some people here hates the current monetary system. The worst part is that these people makes no sense, they cant give any good reason as to why they even hate fiat, they just feel like the cryptocurrency will give them freedom and make them rich, lol.
Cryptocurrency gives you no freedom, the government will still control it if they wish. I dont support cryptocurrency, but I like it. People just needs sense of reasoning.