Cryptocurrency is just a fiat in a modern world. They can be distinguished in some nature but their uses and relevance are comparable. The good thing with crypto is that it is decentralised and cannot be controlled by one. It also has its fixed nature.
I disagree, the name fiat currencies implies what they are, fiat means decree, which means fiat currencies have value just because the government says they do, cryptocurrencies have value because in aggregate people have decided that they do, it is the opposite approach to fiat currencies, and in the case of bitcoin there are also many other differences, like the limit in the amount of coins or that you do not have thought KYC just to create a wallet like what happens when you open a bank account, that makes bitcoin many times better than fiat currencies.
Both can be used for payments and as a store of value,Both rely on widespread consumer trust in order to function as a means of exchange,Fiat money is issued and controlled by (central) banks and governments,Bitcoin is produced and distributed through a process called mining and is not controlled by a centralised authority,Bitcoin can be trusted because it is tamper-proof and cannot be spent twice.