I can think of one: if you get paid in Bitcoin, having to buy some GBPs just so you can buy a coffee or a sandwich is a hassle.
Do you think your answer is in the spirit of the question?
Cash is used for some pretty shitty stuff too, so are credit cards, and checks, and just about every other form of payment.
And funnily enough, Bitcoin is about the dumbest thing to use for illicit things, as it's so easily trackable and records of the money's movement is forever carved into the blockchain (so even if it takes someone 10 years to track the money, or even realize it needs to be tracked, it's still going to be there).
But what about the valid and legal use cases of:
1. paying for goods and services without having to give the company i'm paying access to my account information in a way that they can charge more whenever they want, or lose my information and put my financials at risk
2. Receiving payment for goods and services in a form of money that you don't need to worry about "chargebacks", "reversals", or any kind of way of taking money back after it's been sent
Combine both of those things, and I could see a very real reduction in costs of doing business in just about every area.
If you had the choice between a form of currency not controlled by a bunch of extremely corrupt entities that is much more convenient and cheaper in terms of storage and transactions, why would you use traditional money? I can't even transfer money to my friend overseas, it is too difficult.
I realise that I haven't been clear.
The point I was trying to make is only that you don't need for Bitcoin to be a replacement to visa in order to justify current skyrocketing valuation.
I would venture that Bitcoin's censorship-resistant store of value use case is enough to justify current valuation.
I respectfully disagree with the idea that Bitcoin's killer-app is to be used as a currency for transactional purposes.
I can't really think of many reasons why you would use crypto to pay for a coffee or a sandwich if you live in the West (or frankly, even most developing nations).
On the other hand, I can definitely see the utility in a censorship-resistant digital medium to store wealth. To me, this latter use case has much, much more potential to serve the unbanked (as well as the banked).
Some use cases I can think off the top of my head:
(1) You are from Syria and need to flee war and escape into Europe – however bank transfers into Europe are almost impossible if you are a common Syrian. Bitcoin allows you to take your wealth with you, in your brain, as you escape across the border, by just memorising your twelve word private key.
(2) You are from Venezuela or Zimbabwe – The government has issued capital controls and is devaluing currency by the day. You transfer your wealth into Bitcoin in order to offset capital erosion due to hyper-inflation. When the situation stabilises, you transfer your Bitcoin back into fiat.
(3) You are Saudi billionaire Al-Waleed bin Talal. The government freezes all your assets in a political coup. If you have a portion of your wealth in Bitcoin, you could protect them from government expropriation and anonymously transfer them to associates or family members abroad.
(4) You are whistleblower Julian Assance and have been cut off from the financial system as a way to censor your speech. Bitcoin allows you to have an unbreakable digital "Swiss bank account" that the authorities are not able to reach.
This reminds me of Peter Thiel's recent words about Bitcoin: "it's like a reserve form of money, it's like gold, and it's just a store of value. You don't need to use it to make payments."
Reference
[1]: https://www.cnbc.com/2017/10/26/bitcoin-underestimated-peter...