'USDC' which is a dollar-backed stablecoin issued by Circle/Coinbase is essentially the United States' de-facto digital currency. The advantage of a cryptocurrency vs a normal dollar in your bank account is that the ERC-20 version on Ethereum is 'programmable' - ie can be used in smart contracts for all sorts of things from borrowing/lending, to market making, to exchanging or staking. You could write a contract that drips USDC into an account to pay your bills, I dunno. There are endless possibilities. For me, I prefer to have my money in USDC because it provides a lot more flexibility on what I can do with it than simply having it in a bank account.