Bitcoin might excel if currencies like the dollar et al trips under a hyperinflation scenario ...
wether Bitcoin can replace normal currencies ...
bitcoin is not supposed to "replace" fiat. and it was never the plan. it is like saying when Paypal started back in 1998 it was supposed to replace all traditional money!
bitcoin is like an option, a secondary currency that is decentralized and free of censorship and government control. anybody from anywhere in the whole world can use it the way they like without answering to anyone.
Why then should people invest in or buy a currency that can rise or fall by 20 percent in an hour or two?
this has nothing to do with bitcoin being the "next big thing" or "replacing fiat".
and to answer your question, many people are investing in bitcoin because it is volatile! you don't see a trader jumping up and down saying the asset i bought to make profit is not moving at all, woot woot.
I agree. It does not really intended that when we say Bitcoin and the other types of cryptocurrencies will be the next big thing is we are already trying to imply the replacement of fiat. It is just that Bitcoin and the other cryptocurrencies are into their peak and continuously rising in popularity and usage that is why people considerably saying that it was the next big thing. Putting aside, fiat will still being used by many people so as crypto and there is no need for a one type of currency to be gone just to make way for the other one.