Structure with @BrowserCallable

So far I’ve structured my Hilla projects with an endpoint layer and a service layer, where the endpoint classes contain ‘dumb’ methods that simply call a method from the service layer and return the result to the frontend. But when reading the blog post about Hilla 2.2 I saw an image where a service class is annotated with the @BrowserCallable annotation. Is there a recommended approach in Hilla, should I keep the endpoints and service classes separate or can they be combined as the image alludes to?

Here is a long discussion about the naming of the annotation, recommendations about usage and so on: a lot of mixed discussions and probably opinions