If talking about cryptocurrency will replace fiat currency for me it is very difficult.
Both should be co-exist. The stable coin will need the help from the fiat money to make it becomes stable.
Fiat will always be needed by people in our real life while crypto will always become an alternative payment system that totally pegged with the fiat(stable coinO
People should never think one will replace another.
That might not work again. It's an impossible thing to happen