One of the major question we face in this digital age is how longer we will continue to rely upon fiat currency.
However if we compare fiat vs BTCs richest I will go with BTC because it's a precious gem where you cannot able to elaborate how profittable it is. Also there are big whales who are holding thousands of BTCs and waiting patiently. They are not expecting any popularity like Jeff Bezos
One day fiat currency will be over ruled by BTC because of its dominance is more faster...
Cryptocurrencies are already overruled by BTC. They've always been and they always will be. If we ever stop relying on fiat, we will turn to the digital fiat which is an even shittier idea.
Our society hasn't been educated about this. In fact, we've been taught that accumulating fiat is what we need to evolve in life. We've been taught that we need to buy clothes in order to look good and stay up to date with the trends. We've been all taught the wrong stuff and only now will people start learning what they should've invested into and what they should've done their entire life.