Yes, I live there as a US citizen without access to EU banking, do you? It also worth noting that it is utilized by non EU member-nations, too. (See link below.)

I also happen to live in a country that hasn't adopted the Euro, it will soon but hasn't yet. I also pay my rent to somoene who lives and works in a Euro based country.

Thus direct transfer with Euro to non-Euro accounts (and vice-versa) requires fees, transfers, and conversion costs. And it doesn't operate 24/7, and they never have; weekends always have delays--I paid a friend from Switzerland in BTC to pay someone in a SEPA non-euro EU member nation for a deposit on an apartment before a flight on US time on a weekday (weekend in their time zone) and the funds arrived in less than 10 mins for 17 cents via BTC, the payment to arrive to from a Swiss bank account to a non-euro bank account took 3 days to arrive and clear. SEPA is what Switzerland uses, even though its not a EU nation [0]. And I used to live there when the CHF was pegged to the EUR and was accepted just like the CHF: there are payment rails that never changed as a result.

What I'm saying is things are more complex tan you are making it out to be when it comes to fintech and unless you work in it you will never truly understand that--what some deem edge cases are quite typical if you work in this Industry.

I think your POV is still based on the idea that things are working under ideal conditions (or near them), where as the Bitcoin network was designed to bypass and rout around all those inconsistencies and all the constraints when it doesn't operate as it should. Which is typical for the vast majority of the World's population.

I'm sure your measure of 'functional' vastly differs to someone who operates a legal and legitimate business, but because they are deemed someone who is either high risk or simply persona non-grata for working in an Industry the State doesn't like they cannot gain access to a bank account.

I think this is really the best 'check your privilege' moment we will ever have in the tech space, and most people on HN (mainly affluent tech workers) have as you expected failed in remarkable manner; instead of the woke BS that it's often used to explain people's insulated existence, this usecase clearly exposes how naive and coddled citizens of the developed World are to what are common and typical issues in the rest of the World, but since it has had almost no impact on their own day to day they not only ignore it but will go out of there way to criticize they have a glib understanding of at best.

I can make more sweeping generalizations, but I'm not sure it will be of any use.

0: https://gocardless.com/guides/sepa/countries-sepa-zone/