it's just different.
crypto or bitcoin is functional, in addition to payment it can also be used as a trade with a large profit.
while traditional money can even be traded but the profit is not as big as crypto. so I think it's clear crypto is better than traditional money
This is one of the properties of Bitcoin which has high volatility, where when Bitcoin is compared to FIAT, the price of Bitcoin will always be unstable,
From the nature of bitcoin, humans make the functions of these two elements different. FIAT is still used to transact globally, while Bitcoin is now more inclined to investment and speculation.
This completely does not guarantee the state of Bitcoin will be as you imagine, because the main purpose of Bitcoin was created to be the latest alternative payment that is more secure in p2p.
I think it is used to invest and speculate, yes, but it could also be a good tool to get large amounts of wealth from one country into another. As I am not a multimillionaire or billionaire, I don't know what it costs to transfer sums of money of that magnitude, but Bitcoin has proven over and over again that especially for larger amounts the fees are absolutely negligible for international transfers.