The origin of an event is used for filtering. It's meaning is not the source of the publish of the event, but the actual resource subject to the event (as cause).

I would expect the origin to be set to the dataset_id, so that this event appears in the change list to a dataset resource

The origin should not be the ingester process or whatever, because this is internal system knowlege. It's not interesting knowlege to filter events by an acting worker process

If you need this knowledge, it can be a separate attribute of the event.