Currently questions closed as duplicate are what I will refer to as singly linked. A link appears on top of the closed duplicate question pointing to the original question. Nothing is added to the original question. Sometimes the duplicate question has useful answers and comments. By definition, we marked it as duplicate because we think the question itself has useful terminology and wording that is helpful for future searches.
I propose that whenever a question is closed as a duplicate, a link should be added to the original question pointing to the duplicates. This would only be viable if it was an automatic process and did not require any suer intervention beyond simply voting to close the question as a duplication. Obviously some question may have a lot of duplicates so this list would need to be dynamic, realizable, sortable, and possibly searchable. The idea would be to allow a new user to easily find all the knowledge on the site about the question.
Maybe this is better for the main SO meta, but I haven't really thought about how this scales by a couple of orders of magnitude.