The point is that nobody can really say that all tether is bought this way, that there is a genuine flow from cash to the tether company to exchanges, and there are very reasonable suspicions that tether is just magicked into existence for use on friendly/complicit exchanges to help control the price.

Perhaps I should have said it's less a question of how tether is bought and more a question of if tether can be said to be bought, at its point of origin.