I think this could be changed but for now it is very difficult to achieve it, if crypto replaces fiat, of course there will be many negative and positive impacts, such as payment transactions will be fast, and the shortcomings as well as when the transaction is disrupted will disrupt the process
I guess that a few people use crypto instead of fiat even now. Nevertheless, if we speak about the whole society, it is not possible that virtual money could ever replace traditional currencies. People need fiat more.
Right, the government has been controlling the financial system of this world, fiat is the most popular now and even if bitcoin is gaining popularity, fiat will still be widely use by the people, and that's because of the trust since it's the government that created the money.
Bitcoin on the other hand is decentralized, we cannot force people to use to as it's not also regulated and this should not be in full regulation since it's purpose is just a payment system which is an alternative of fiat.