I disagree with you; fiat currency will always continue to be here. Even if there is rapid acceptance of digital currency, fiat still has a place and will continue to be here. Aside from it having something to do with our economy, not everyone out there can make use of digital currency. Even with the traditional banking system, they still don't; they prefer to go with cash unless you are proposing a total collapse of a system.
There is no way fiat will be useless fiat will always be useful and still be use for exchange of goods and services while Bitcoin will also be in existence. There are people who can't use Bitcoin some traders in the market some doesn't even know what Bitcoin is all about so while others will be using Bitcoin for other payment and business transaction fiat will also be use for payment and other business transaction.
And fiat should not even be compared to Bitcoin or seen as an enemy to Bitcoin; neither should Bitcoin be seen as its rival. Both have their path to play, and those who are using Bitcoin for every other thing aside from the security and privacy reasons should do it, while those who are with fiat should do their thing. Aside from the local traders on the market not knowing what Bitcoin is, fiat is one thing that's representing a country and also a means of their identification.
