Goods and services traded internationally are priced in whatever the parties want.
Ultimately they want to exchange for the currencies they need to pay bills, wages, and taxes in.
"Reserve" currency has little to do with it - if anything it's the high volume of trade with USA that makes it worthwhile to keep reserves of USD, because the high volume of US trade means you get many chances to exchange USD for whatever currency you actually need.
Ultimately they want to exchange for the currencies they need to pay bills, wages, and taxes in.
"Reserve" currency has little to do with it - if anything it's the high volume of trade with USA that makes it worthwhile to keep reserves of USD, because the high volume of US trade means you get many chances to exchange USD for whatever currency you actually need.