Would banks and governments actively work and implement countermeasures to undermine this process? Are the underestimating the potential of cryptocurrencies by investing in some of them?
Do you think there is a possibility of cryptocurrencies being banned in the future for the reason of being a threat to "normal" currencies?
It is for sure that government wouldn't allow cryptocurrencies to takeover fiat currencies. They wouldn't let something they can't control rule. If cryptocurrencies outpace cash in terms of usage, traditional currencies will lose value without any means of recourse. Should cryptocurrencies take over entirely, new infrastructure would have to be developed in order to allow the world to adapt. There would inevitably be difficulties with the transition, as cash could become incompatible quite quickly, leaving some people with lost assets. Established financial institutions would likely have to scramble to change their ways.
You are talking about the decentralized crypto currencies only. Indeed, these cannot be controlled by government and they also can’t have any record of transactions made in such coins.But if countries introduce their own crypto currency like Dubai or like Mark has introduced one recently, it won’t be wrong to say that paper money can get wiped out by digital currencies.