$300 million transferred, fees of $0.04, confirmation in 4 minutes.
Now imagine the hoops you would have to jump through to transfer $300 million in fiat, the days of delays, the fees, the people you would have to discuss it with first, etc.
It is a cheap transaction by any measure. But with all that hassle that fiat transactions of that size bring on, you can be sure that your money will end up where you intend it to be. Besides, if we are talking about a contractual payment, the details of the transaction will help you tremendously in court if something goes wrong, for example, your counterparty fails to deliver. With crypto, it is still possible, but it will be a lot harder.
And I'm not talking that there is no way back to get the money if you send bitcoins to a wrong address. To err is human, and such things do happen, while with fiat it is not a big deal in the majority of cases. If you make a mistake, your payment just won't be processed. With bitcoin as well as other cryptocurrencies, you can easily send funds to a non-existing address, that is an address from which no one has the key yet, and you are instantly out of options. Yes, I know you can't use just an arbitrary combinations of characters in a bitcoin address, but this will be cold comfort if you are "lucky" to pass the checksum.