Both can work together to achieve a far greater financial goal but people will always fall back to fiat in the time of recess as we've seen during this pandemic.
Fiat is also a great way for us to see our profits physically, and we can save even more profits because of fiat, how? well you just have to sell one of your tokens in a high price and then spend your fiat while you're waiting for another ALL TIME HIGH price, simple as that, because if they will not coexist with each other, our profits will also fade away in a point which we will never notice since all we care is that it will pump again anyways.