That's kind of the thing though. REST doesn't do transformations. It just does CRUD of resources.

For me, when designing an application, I will think, "is representational state transfer the only thing this application will ever need to do?" If the answer is "no" then REST seems like a poor model to build around. I've never answered "yes" to that question. (That said, I spent many years mindlessly building REST apps before I started asking myself that).

Per CQRS etc., that's right. It's a tool. Use it when appropriate. Don't use it when not. (That said, the scare factor of that article is a bit high--I've had very little trouble with it since switching to it as my go-to update pattern about five years ago. Also note Martin Fowler has changed his mind on several topics lately, such as the Rich vs Anemic domain model, away from OOP and toward a more FP viewpoint. CQRS is certainly the more FP model here.)