Which ones? Every crypto that gets any amount of usage immediately hits up against deliberate scaling limits in the consensus mechanism[0] and stops being a use

Which ones? Every crypto that gets any amount of usage immediately hits up against deliberate scaling limits in the consensus mechanism[0] and stops being a useful medium of exchange. Cryptocurrency also has extreme speculative risks, which means that it's useless as a unit of account or a store of value. Fiat currencies don't have these problems[1]. Because they are instituted by a government that forces people to use it, they have a large volume of economic activity which makes it harder for the currency to swing dramatically in value. The reason why Bitcoin can fluctuate so wildly is because few actually use it like a currency, so there's nothing to buffer against market manipulators and forex speculators. [0] Because crypto needs global consensus over every satoshi in the system, all transactions need to be widely propagated to all full nodes, which imposes strict limits on how much transaction data can be processed at once. If the limits are too high then only large institutions can run full nodes which is centralizing. Of course, literally everything else in crypto is centralizing, because centralization is the gravitational force of economics. [1] No, Zimbabwe doesn't count.