This has been several times that some people say about Bitcoin that will replace dollars or fiat, or crypto that will replace banks soon.
Well, actually it may be possible, but I am not sure this will be easy and will be done during these 20 years or more.
And maybe, this will not happen.
We know that dollar, other fiat, and banks are centralized, controlled and managed by not only government in each country, but more than it, by a big power behind the world bank.
And , I ma not sure that even this is a digital era, they will let Bitcoin replace fiat. We all know that today, they also crypto develop their services to fit to this digital era, more technology advanced development.

What I think is that Bitcoin will be probably used as one of the global currency, accepted by many more countries and merchants as a currency, less ban and others. But this will not replace.