That's fair, but it's probably an improvement in regions blocked by more traditional financial services. In many of those regions, people may not even want to cash out to local currencies as holding a digital dollar is often more stable.
That requires a rather unusual confluence of events.
Almost everywhere there needs to be a on AND off ramp, or only the most diehard hobbiest or desperate economic actor will consider it. This stuff is just too new, and there is too small an ecosystem for all but a small handful of coins for them to actually act as a useful exchange medium.
Genuinely curious, what alternative solutions do you see to the underlying problem highlighted in OP's post?
The ones they usually use right now - holding physical USD, bartering, physical gold, real estate, etc. depending on the use case and degree of wealth.
Local currency does still get used, it’s unavoidable, and causes losses. There is no perfect solution.
One economy which fits the description is India - check out the boxes of cash hah! [https://www.livemint.com/Politics/eGzzHAcOe5VePoyCd7n0EN/Inc...], and [https://timesofindia.indiatimes.com/city/mumbai/mumbai-raid-...].
(FYI, a cr or crore == 10 million, a lakh == 100k. Even at current exchange rates, that is a lot of money anywhere, and an absolutely massive fortune in India).
But there is an element of this in ALL economies, including the US. It’s a matter of scale/ratios, not a yes/no thing.