I like the idea of cryptocurrency as a mechanism to keep track of how much of some token (abstract thing that can be used to represent any functionally finite resource that is traded) each individual in a group owns. It solves the similar problem as fiat money but works a bit different.

Crypto should in theory be safer than traditional banking system where anyone that possess your checking and routing number can pull or push money into your account pretty much willy-nilly (Technically it needs your approval in the form of a physical signature or approval but that can be spoofed) and I do think governments could benefit from a proper form of digital currency or really having each individual be assigned at birth something more secure than a social security number! As I understand, Europe relies on something called SWIFT which I understand to be like a giant colossal version of Paypal or Visa, for banks. (I don't know much about this and would like to know more)

Crypto leverages the power of asymmetric keys to ensure only the person that knows the private key can move tokens from their "wallet" into another wallet for which they know the public key. The block chain decentralized ledger simply keeps track of how tokens get moved.

You can see there are a number of limitations crypto has compared to fiat through: the public key (which is public!!) is all that needs to be known to see ALL the transactions that this wallet has executed. If Tom has this wallet and you know his public key for his wallet, you can see the account history of all the transactions he made on the public blockchain. Also only the owner of the wallet can execute a transaction. I consider this a good thing for security.
In practice, cryptocurrencies like BTC and ETH and all the other lesser ones aren't really being used as currency for a number of reasons, but instead dominated by people pumping and dumping and using this technology as a speculative dumpster fire.

I had more faith in the big "brokerage's " (Binance, FTX, coinbase...) that promised that they take your crypto, providing an "I.O.U" on the money you deposit and pay out some APY as a return. Well the TL;DR is underestimated how bad the crypro situation got and potentially have lost a bit of money.