Bitcoin's rapid price development from 2020 to 2021 makes people feel a little crazy. From 6000 US dollars to the current 54000 US dollars, huge profits and capitalists attracted us. Overthrow the dollar hegemony? World currency? Block chain? Decentralized? , There is no substantive thing as a guarantee for this. To be honest, I also have investment, but only for profit.
This is why you choose bitcoin for your investment right?
As for your concerns, bitcoin will crash since long time ago if there is no substantive thing, but as you can see now its price just make many people regretted to not buying it at the low price.
More than that, if bitcoin doesn't have a function then I guess there is no significant increase from its lower price $3500 because previously its price had been increased to $20.000 and crashed to $3500 but as we can see now $56.000 is a high price for an investment place.