It’d be good if more transactions — especially debts — were in national currencies but I suspect it’s going to be a very long time before international trade uses another currency. It’s just one of those things where there’s tons of inertia. Like global shipping companies have contracts and processes that assume dollars. It’s just cheaper/easier to use dollar contracts than have a contract for each currency.
Global reserve currencies have changed before but surprisingly rarely. It kind of requires a huge shock (like WWI) to force the world to change.
Argentina had a unique situation where they forced Argentinians to use their currency by mandating a very unfavorable exchange rate for the US dollar. However, Argentina really likes American tourists and businesses spending their dollars in the country, so they had a different, more favourable, exchange rate for foreigners.
This caused a glitch in online credit card processing that resulted in people receiving a 40% discount on online purchases if they requested to pay in Argentinian pesos. The site would charge a high amount but their credit card statement would be a lower amount since the two used different exchange rates.
Most medium to large countries probably have something like this in the works, even if it’s quietly handled behind the scenes. It doesn’t matter if you are currently getting along with the US; a dependence on the US financial infrastructure is obviously a long term national security threat.
