Well to be fair El Salvador is still on the fiat standard. They are a dollarized country.

No country has adopted the Bitcoin Standard.

My guess is that it will be decades before we have sovereign territories that are Bitcoin-centric enough to consider them on the Bitcoin Standard. And credit/fiat instruments will still persist, just, I think, to a much less significant degree to today.

Large-scale nation-state mining, replacing "modern" fiat central banking with Bitcoin treasury management, and taxing in Bitcoin (as opposed to taxing in fiat) will probably be some of the biggest indictators that a territory is a Bitcoin Standard.