There's no money worth 7000 dollars. Bitcoin can be worth the price but with this store. People see bitcoin as an investment instrument. The instability of the Bitcoin price scares people. Offers an opportunity for people. And that attracts people. Uncertainty excites people.
There is no money that is worth 7300$ today and was 3800$ on 1st March 2019. Is it wise to say that global fiats will crash one day? I mean who gave a surety of that? Even if fiat crashes, bitcoin is in no position to replace fiat as its too volatile, have a high transaction fees and settlement time. Tune-up bitcoin first if you wanna see him replacing fiat.