> Can you explain how this is better than e.g. Wise (formerly Transferwise), PayPal, or some other international money transmitter?

The short answer is that Bitcoin works and TransferWise and PayPal don't. I looked into TransferWise a couple of months ago when someone else asked about it: https://news.ycombinator.com/item?id=26657391

I can't get an Argentine bank account, and you need a bank account to use either TransferWise or PayPal. It's probably also the case—though I don't know for sure—that such transactions would happen at the "official rate", which is to say, you get 62% of your money, and the other 38% gets taken by the Central Bank to subsidize imports into Argentina and vacations abroad by Argentine tourists. I know that sounds too crazy to be true, but that's really what happens with bank transfers. Western Union doesn't do this, and if they did people wouldn't use them.

> Bitcoin does not solve the “cash to people without a bank account”.

This is not correct. It does. I can't access a bank account and I get paid in Bitcoin. It's true that I pay Bitcoin transaction fees in order to do so, but they are generally tolerable.

> If the idea is, that people should instead transfer money to each other via the Strike app, when they pay for things, I fail to see how this is different from e.g. sending money to each other with PayPal.

PayPal is exposed to a lot of risk of fraud because of being connected to the banking system, and it passes that risk along to its users.

A friend of mine had his laptop stolen via PayPal (in the US). He received the payment on PayPal, a woman came to pick up the laptop, and after she left the payment was reversed. He disputed the reversal, but because he couldn't produce a shipping tracking number, PayPal automatically rejected his dispute.

There are several cases of conferences that have done conference registrations through PayPal and then had all their revenues confiscated because PayPal decided that their pattern of transactions looked like a high risk for fraud (new account, lots of incoming money, no shipping tracking numbers). Linking your bank account to your PayPal account means that PayPal can, at any time and at their discretion, take all the money in your bank account, and this is also a thing that happens.

And of course it's widely known that PayPal discriminates against prostitutes and porn models and people associated with them, closing their accounts without notice when it discovers them, and sometimes confiscating their money.

These risks don't get smaller when your customers are the unbanked; they get larger. And passing those risks along to people who are living hand to mouth is unacceptable: temporarily losing access to your money is a much bigger deal when you can't afford to fill the gas tank more than halfway full because you don't have savings to cover gas for your car. Or food for your kids.

I don't know anything about Strike as such, but using Bitcoin itself eliminates those risks, although while you're holding Bitcoin, it does create cash-like risks of its own—exchange-rate volatility, seed phrase loss, and theft by trojans. Good people tell me the Lightning Network design has a similar risk profile to Bitcoin itself, but I don't understand it well enough to make such assertions on my own.