I know about that, I am in touch with some people from there (and I even speak a bit of Spanish 😉). However, it is just a drop in the sea. Currently, there's nearly $8 million in Savings. And here's a graph of Monthly HBD transactions taken from this post:
It means, that the interest paid out on Savings deposits this year will be higher than the average monthly HBD transfers. Besides, not all of those transfers are actually payments. In fact, I am afraid that most of them are not payments.
HBD has been a failure and being promoted as an active form of exchange is dishonest at best if not deceptive.
I would rather say we don't use it the way we should. It could be a great tool, though. I am just thinking about writting down an article about that soon.
I think, like you said, it is only really useful for those paying things in fiat in a future date if you want certainty. For paying straight away, people can do an instant conversion easily like any currency. Then the 20% hubris has come in and taken over.