There's also infrastructure to consider. Like. Good luck switching rural Alaska to crypto. And Texas, since they learned the lesson very recently that when the power is out you can't use anything but cash. You aren't writing a transaction to the blockchain from the Khyber Pass.
Crypto as the money of the future is only viable in small countries with a lot of population density, so I can see why P3nt sees it as inevitable, but it's not realistic for most of the world, because poor people and rural folks need to engage in commerce too.
Blockchain as a replacement for the financial infrastructure of the world is one thing (the bonus features of Ethereum do legitimately have massive utility and something like that is a very good replacement for electronic funds transfer as we know it), but fiat currency will not go away, because it remains more useful than crypto in most circumstances no matter what happens in the future.
So. Yeah. Bitcoin and its relatives are no-hopers in the future. Blockchain has a chance, but it would replace the backend of plastic, not fiat currency.