> A visitor is not going to be buying meat at a grocery store, they are going to be eating out.

Having done longer stays, gonna disagree with that. Grocery shopping in other countries is great for saving money and getting to experience the place.

> And if they for some reason were buying groceries they are going to be more concerned about the currency conversion than the unit of measure. Come on. I mean what benefit is there really?

Low-level: Gas in Denmark right now is 14.66 DKK per Liter. "What's that in FreedomBuxx?" You usually have the currency conversion squirreled away in your head when you're in a country for a while. If you can think in Liters, you can do "1 USD is a little under 7 DKK so it's a smidge over $2 and change for a liter" and you're done. If you can only think in gallons, you do that, and then also have to convert 3.78541 liters per gallon, which yeah, you can round to 4, but it's another conversion. And while you might have "a liter is a quart, for small use cases", it's a second conversion and this pretty much where brains blow up. (Answer: it's 8.12 USD/gal).

High-level: We're on an island of Imperial units, and that's isolating to commerce/tourism. It's fine that we're 'the exception' while we're the 800lb-gorilla (363kg) economy but, someday we may not be. We doggedly refuse to believe that there could be any long-term (generations-length) benefit to the local+world economy that could outweigh the (amortized over generations) costs... to the point that the idea of starting a systemic/slow conversion seems too much, because we can't see what's on the other side.

I get you're not convinced. I'm sorry.