There certainly have been some countries where stablecoins have gained in popularity. They are a little easier to use than bitcoin and prices are more stable. It tends to be in places where governments are not heavily enforcing against their use, while at the same time the local currency has been unstable, such as in Argentina.

Yes, I think this really is a use case even if it's not one that flatters the prejudices of American bitcoiners. People from non-US countries want access to shadow-dollars, yet the US has built a large and intrusive industry based on keeping them out.