You are diluted. The US dollar is the world’s reserve currency. It’s the US’s job to make sure the world banks are properly funded in US dollar or, any excuse will do.
You can buy bonds from the US Treasury but the Federal Reserve distributes the cash/credit and by looking at the article, distributes at will worldwide.
Because when people do international transaction they prefer to do it in dollars.
They trust the dollar more than other currencies. They would rather hold the dollar than other currencies, and they'd rather receive payment in dollars rather than other currencies.
They can trade in any currency they want to or any combination of currencies they want to. There is nothing stopping them. There's no international law declaring us the reserve currency and saying they have to trade dollars. They choose dollars.
You are mistaken. Clearly I am concentrated.