If there's a dupe question it usually means it's a popular topic, or there's a demand for a solution to a certain recurring problem. Sometimes we close dupes in reference to old, unanswered questions. This doesn't really get us anywhere.
I suggest that when a question is closed as a duplicate, and the post it is a dupe of has no accepted answer, then said post should be bumped to the top of the home page question list.
Especially for old questions that haven't been active (by any means, like editing or being bumped by Community) for more than a month or so, this would be very helpful. The point of closing as a duplicate is to give more attention to a previously asked question addressing the same subject (also to clear confusion, since it's better to have one resource than two or seven), so in cases of old questions, it doesn't do much justice.
(Here'sHere's a meta example. The question it's a dupe of was asked in November of last year and has had no activity since. A comment was posted recently, probably because of the link to the question in the recently posted duplicate.)