2.If you imagine in let's say 20 years FIAT goes to CRYPTO all the way. You want to buy a car worth $5000 but paying in Crypto, how much would you pay ? if $ got no value.
This is not gonna happen, bitcoin is a good payment system but we have to understand that it will still remain as an alternative, fiat will never replace by anything that is out of control by the government especially bitcoin is even a decentralized form of money.
I agree that bitcoin is a great mode of payment however it comes with a selected moment only so in my opinion it is not that efficient. Bitcoin is great in peer to peer transaction since you can transfer it seamlessly, things are different when you are sending it internationally and in an exchange coz it will take longer time plus the transaction fee is high. Fiat on the other hand will never get replaced, that is an absolute thing that the government is making to do. What a nation need is a centralized currency, not a decentralized one.