While all of this seems to be more of a dream than anything else, there's a possibility it could happen in the future if people lose trust in governments, central banks, and conglomerates alike.
There's a very little possibility IMO.
I guess not, it would be chaotic for me since there is no governance in all financial terms at all and if there's no one to control it might be disastrous for all of us inside the crypto.
Look at the country that loses their trust to their government, the country is not progressive anymore and there's a lot of crime happening.
We don't want that to see in the future, that's the reason we elect government officials to implement the law and govern people.
What country are you referring to?
Fiat will remain, bitcoin or crypto might grow but it will not be as acceptable as fiat, there's a limitation on using crypto as whether we like or not, we are still subject by the law which the government has the power to implement it, and let us not think if they still believe they have the trust of the majority, they will always put their interest which they think good for the many, and IMO that is not crypto.
Cryptocurrencies does not really created to replace the fiat, what its purpose is to add an option for people to use when there is a distortion on the other system just like what VISA did, they did not replace the fiat for crypto instead they add a crypto on their list so people could use their neither fiat nor crypto in any transaction. I see the point of yours, if we want to be a cashless society then we should not be having a decentralized one, on this case best if we use the digital payments method.