Honestly I do not get bothered with whether cryptocurrency will replace fiat or not. Only time will tell. This is  a day's job and not only sweet saying. What cryptocurrency and blockchain technology will do is what the world is waiting for. Lets join the train and be part of history.

In my opinion, well, even though bitcoin will not be able to defeat the fiat currency it will have a good and bad effect on bitcoin users with their own perspectives. For me, it wil be a good effect on bitcoin because if bitcoin will defeat fiat currency then there is a chance that the government will held the bitcoin and start to regulates the cryptocurrency. So, I think it is better that bitcoin will not surpass in bitcoin in terms of usage, but in terms of price I thinks its bitcoin.

Yes i also think that crypto currency never replace fiat currency because it still doesn't able to gain the trust of people. And cryptocurrency are not a globally accepted currency. It is still not clear to many people and it is too complicated to understand. Many government ban cryptocurrency in their country because cryptocurrency badly influence their economy and financial growth. Cryptocurrency are volatile in nature and it is one of the biggest behind this topic. Cryptocurrency are decentralised so if any thing wrong happen no one take responsibility of this.

The way I see it, crypto currency is not replace fiat but to work alongside it. Just like credit cards and bank transfers work along side cash.

Cryptocurrency cannot replace the fiat not a problem for us. Users of cryptocurrencies do not allow it. Anyway, this is not the purpose of created cryptocurrencies. Fiat is the currency of a State. The state must have a centralized currency. It should.

Cryptocurrencies are suffered from many shortcomings including its intrinsic characteristics like anonymity. Transactions not requring personal information advantage criminals in illegal activities. In short, there's no way that virtual money will be an alternative for fiat money.

Digital currency is complicated to control. In case crisis or hyperinflation happens, the Central bank can hardly to offer suitable policies, while it's much easier with fiat money, which is under the central bank's regulation.

It is very true and I don't think most of us have even thought of cryptocurrency replacing fiat. Not everyone in our countries have the technical know how to understand cryptocurrency and so to replace fiat with cryptocurrency will mean total doom for such people of which no government would want to do.

Cryptocurriencies are online currencies and hence are not the same as fiat. Even though both currencies are aimed at the same purpose ie buying and selling, their mode of operations are different. So do not expect crptocurrencies to replace fiat. They would rather work hand in hand.

In my own opinion,  cryptocurrency can never replace fiat currency. Fiat currencies will continue to dominate as long as there are nation states and governments are powerful enough to enforce their laws. Fiat currencies exist because the alternatives, such a gold, ultimately failed to meet the demands of the modern world. Bitcoin is similar to gold, but actually worse in the supply is even more constrained.