<p>There is not enough benefit of keeping such questions to undelete them. Yes, they may make finding relevant questions easier, but on another hand, they add to the overall &quot;noise&quot; of the multiple questions and answers we have. I would say that there is no harm in keeping them, but also no harm if they are deleted. We want to keep the <a href="https://meta.stackexchange.com/questions/32311/do-not-delete-good-duplicates">good duplicates</a>, not all the duplicates.</p>
<p><a href="https://meta.stackexchange.com/questions/10841/how-does-duplicate-closing-work-when-is-a-question-a-duplicate-and-how-should">See also</a></p>
<blockquote>
<h2>Should duplicates be deleted?</h2>
<p>In general, no: most duplicates stay around. Having multiple copies of
the same question with different wording is useful as search fodder,
because people looking for an answer may use different wording too. On
the other hand, duplicates that are word-for-word copies or that are
so poorly written that they are not useful may be deleted by users
with sufficient privilege.</p>
</blockquote>
<p>So again, we want to keep most of the duplicates, but there is no need to keep them all.</p>
