Its inevitable for Crypto to replace fiat completely. But still 10-20 years imo
That’s not gonna happen, fiat money wont be replace by cryptocurrency maybe fiat money will become more on a digital platform but it will never be replaced by any cryptocurrency.
Stable coins on the other hand is not a credit, so technically it wont replace credit cards and even a debit card. Stable coin is good to protect your income, it can’t replace fiat money though.