That's certainly true, mate. Everything will depend on the collaboration from both people and governments worldwide, for a digital Fiat currency to function as intended. The process will be a rather slow one than usual, since there are many people that are still accustomed towards using physical cash in their daily lives. Governments would need to introduce their digital currencies in a slow and steady pace, in order to attract people into the new economy. Only then, physical cash will cease to exist in its entirety as our economy will live within the digital realm.
Given how Blockchain technology has gathered the attention of central banks and governments worldwide, it's likely that government-issued cryptocurrencies are the future. No one knows yet what will happen by then, since Blockchain is still not mature enough for mainstream use. As time goes by, the technology will improve to a point where scalability and privacy limitations will be no more. Only then, governments can use this system in its entirety to transform traditional finance as we know it. But as I've said earlier, this will take some time before it becomes fully implemented. In the meantime, we should enjoy decentralized cryptocurrencies as much as we can since they're prone to become extremely valuable in the future once Blockchain awareness spreads wide enough among people worldwide. Just my thoughts