I don't know the exact law in El Salvador, but in general "legal tender" does not imply an obligation to accept as payment in stores, it just means that most debts are discharged if the debtor offers (tenders) to settle the debt using a 'legal tender'.
So, for instance, if your plumber did some work for you and sends you an invoice afterwards then that debt is discharged if you offer to settle it using a 'legal tender'.
However, shopping in a store is usually not the same because payments do not settle an existing debt.
Again, I'm not sure exactly what El Salvador's new law entails.
I'm envisioning a lot of dirty looks from paper cash-preferring shopkeepers to crypto tourists when the tourists buy up all shop's inventory and leave the shopkeeper with just a few numbers in some app.
EDIT: To be clear, I mean tourists each individually buying a normal amount of things using BTC, which adds up to the store exchanging it's inventory for a number in the app.
I suspect the number of people who would actually do this sort of thing is quite minuscule. They could probably be handled with something like "Well tourist, the cops here think it is a civil matter so you can spend the rest of your vacation dealing with the local legal system if you really want to buy everything in this random shop for some reason."
I suspect more likely some rich people will find it more convenient to pay their tax bill.
I didn't mean one tourist buying everything (which would be problematic no matter what the currency was), I meant in the aggregate. I've added an edit to my comment to clarify.
Bitcoins are currently at $45k, so I guess this would mostly just be an issue at a luxury car place, which... should probably prepare to handle these types of transactions I guess. But that's not like Grandpa's Little Old General Store, so I bet they can handle it.
I'm actually curious how this will be implemented specifically. I guess (although I'm not well-informed on the ecosystem) that most of the places that let you do small cryptocoin transaction either use some smaller coin, or they must have some way of doing fractions of a bitcoin, right? In which case, the fraction system would have to be proprietary, I guess? I can't imagine the law required shopkeepers to use any particular proprietary exchange...
Didn’t the grandparent comment explain that in such a case, legal tender doesn’t apply? There’s no debt in a normal shopping transaction, the shopkeeper is free to accept whatever they wish or reject the transaction entirely.
That's how it works in the US but it's mandatory in El Salvador. I believe the dictator there has been threatening folks who don't accept Bitcoin with punishment. Needless to say this is good for Bitcoin. [1]
Bitcoins are at like $45k, if somebody comes in to the local CVS or whatever and buys a stick of gum with a bitcoin, are they expected to have $44,999 in change sitting around? That seems... odd.
So, for instance, if your plumber did some work for you and sends you an invoice afterwards then that debt is discharged if you offer to settle it using a 'legal tender'.
However, shopping in a store is usually not the same because payments do not settle an existing debt.
Again, I'm not sure exactly what El Salvador's new law entails.