As someone who has been regularly transferring money between the US and UK for nearly a decade, using standard banking means has always been faster and cheaper for me than any of the crypto solutions that I've been presented.

It's only cheaper if you and your friend are inside the system. The two eco-system are separated and this makes friction and cost high (if you are onboarding/offboarding liquidity).

Do you believe your own personal experience with those two English-speaking countries can be extrapolated to every other country in the world?

No, I've worked in enough countries to know that my experience cannot be extrapolated to the remainder. I'd love to hear your experience and how this did work out for you.

It still requires getting people's IBAN numbers, which they usually don't remember. Inside each country you can usually send money with just an email account, like Venmo or Zelle, but internationally it's just cumbersome.

Strongly depends on where you are and where your friends are.

It may be useful for transferring money, but not because the technology is inherently better for that.

In technical terms, it costs more for a bank to send an email in between branches than to transfer money in between branches. If, using current tech, some U.S. bank would offer transfers anywhere in the world for $0.20 a transfer, they would still make money, and you would feel much more confident that the money will be available for withdrawal.

Now, I realize that due to various factors, it is not legal to transfer money to all nations, and there are some nations that dont have the infrastructure to reliably get you cash - but those are not advantages of the tech, they are advantages of the lack of laws.

You could build a equivalent, illegal, "bank" with headquarters in, I dunno, Russia? Transfer money worldwide for $5/transfer, and figure out how to avoid the feds. No blockchain, and you have acheived the same.