Full disclosure: I was born and live in the USA, American English is my native language, and I spend USD every day. However, I work with customers in 18 countries and regions on five continents, and the list is getting bigger all the time.
Operating a business in the global market is not as trivial as it might seem, if you’ve never seen it through. Everyone not only speaks different languages and has different currencies (not to mention driving on the different sides of the road), but they also have different cultural norms. In many situations, we can merely provide raw values for dates and currency and avoid formatting. However, when content includes localizable information, especially dates and currencies, display formatting needs to be sensitive to the localized culture.
If you’re considering making the jump off of your own soil to the rest of the globe, hopefully this will give you some insights.