Let’s be honest, it’s principally for illicit use, a tiny fraction of privacy folks and then a lot of people caught in between who don’t understand yield but want to bet on a volatile asset and have to use a stablecoin to go between. (Because the backers of the volatile thing are doing something illicit.)
> stablecoins are commonly used in international trade
For a rounding error value of "commonly," sure. (Catering to a financially-constrained market is good business. But it, by definition, will never be an important one in the grand scheme of things.)
Something can be common, while not representing a large volume. And given the current aggressive policy of the US administration, you may soon have to find new payment rails for your international trading, depending on where you live.
As always, things are certain until they aren't. Technological innovation always starts with fringe use cases, before becoming more widespread.