Its sad but this is the truth and not all would really be that open nor able to make use incase if there would be some full integration from paper fiat to digital if that's the case because
not all would really be reached on the scope on adoption and also people had already get used to fiat.
Its not bad to be that optimistic about bitcoin or crypto but minding about becoming a mainstream and tending to replace fiat is something that is impossible to happen..
Bitcoin could progress but it would really be just as good as an alternative and wont make it as a mainstream.
It is expected that if ever cryptocurrency became a legal tender in every country and utilizes digital transaction in each establishment or business transaction or even a simple person in his/her daily basis not all people could adopt it on their own. This platform cryptocurrency is really a big help but i think the existence of traditional money will still circulate in the economy. Why? Like for example in the third world country, not all people have gadgets or have a capable to buy their own and also this platform takes a lot of process or transaction that a person really should know about.
everything requires a process, of course we can't replace it completely or totally, maybe to be able to do that we at least have to go through 2 generations so that all can access crypto in the internet world. at least being an alternative means of payment is already a good achievement now