If the retooling is expensive or blocked by those with outsized interests (see all the things crypto accomplished whilst being ignored, mocked or even suffering active attempts to stifle) then carry on replacing like any other number of tech shook up financial worlds before it (see also early stories of transactions between banks once computers got involved).I hate to break it to you champ but those were things with actual uses. There's nothing crypto can do that fiat can't already do with retooling. There's no real innovation behind crypto and there's never really going to be. Decentralizing something that so inherently requires centralization like currency is a recipe for disaster. One only needs to look at the myriad of failing coins to see that.
Does currency require centralisation? Issuing banks/central banks of most places in the world whether you would want to live there or not have shown themselves to at best be corrupt beyond all reason (the dual mandate being a conflicting one in the US all but ensuring that, never mind looking at something fun like Turkey or Venezuela) or incompetent (if the transitory drum is not a "nothing to see here" thing similar to them not mentioning the word recession lest panicky types appear then it is incompetence, or a staunch belief in MMT which is... the same thing).
Failing coins is like failing companies. Better to have people try than have none.