It is subtle, but the state is shown. It is open, because the close button is active and the open button is not. There’s not much room left for the state in text. The entities card is meant to show multiple entities in a more compact way.
It also can be used to force entities with a default special row format to render as a simple state. You can do this by setting the type: simple-entity .
But I never understood the context.
Even if this is a huge step in the right direction, I still would like it to be rendered exactly as the entity card does it: