> absolutely awful usability compared to the Euro

In what way? One unpleasant discovery I made in Portugal (and also saw to some extent in Spain) was that ATM’s - every one I could find, including those that were bank-owned at physical branches - had a limit of EUR200 per transaction regardless of my own bank limit (at USD1000/day, that should have been at least EUR800).

And while convenience stores, fast food, etc., won’t take a bill over $20 (which is understandable but really a trifling sum when you consider inflation - it’s a fast-food breakfast for three people), many other businesses are happy to do so. Nothing above $100 is in circulation anymore, and inflation means that $100 in 1980 is worth over $400 in today’s money even by government figures. A $20 bill 45 years ago was worth almost $100 in today’s money. And, of course, cash declaration rules have not updated the amounts to reflect this.