Status flag for Get Activity REST API

Currently the Get Activity REST API only contains requests without a status.

I would like a status column with the following values: Success, Failure, Cancelled, ...

This would be especially useful for: Refresh Dataset, Refresh Dataflow, Delete, ...

There is an existing column isSuccess, but it always TRUE and therefore not useful to anyone.

This column is working as expected according to Microsoft Support & Product ... :-/