Currently, it takes 5 close votes from users with the vote-to-close privilege ($\ge3000$ reputation), or 1 vote from a moderator, to close a question. If the question is being closed as a duplicate of an existing thread, it can also be closed by a single user with a gold tag badge on one of the tags on the question, if the OP had put that tag on the question originally. On the other hand, if there are 3 leave open votes on a question in the queue, it will not be closed and will exit the queue. However, right now (6/25/20) we have 47 threads sitting the the close vote queue. That seems to be typical. Over the past few years, the queue has occasionally gotten into triple digits; it has not gotten to 0 and stayed there long enough to be recorded. If neither voting threshold is reached, the thread will 'age out' of the close vote queue after 4 or 14 days (depending on whether the question has $\ge 100$ or $<100$ views, respectively). I believe there have been many threads that have been unresolved and simply aged away, but I don't know the number. To the extent that threads have been closed or left open consciously, it has been primarily due to action by voters with the power to unilaterally resolve the issue. To a large extent, threads have been resolved due to the efforts of Peter Flom, who has completed more than 15 thousand reviews (thanks, Peter!).
This state of affairs seems suboptimal to me: Many threads are not resolved, those that are often take too long to reach resolution, and too much of the burden and results have been shoulders of too few. I am now wondering how we should move forward. I see a couple options:
- We could continue with the status quo.
This does not seem like a great option to me, but I don't know if others share that opinion.
- We could try to somehow get users with sufficient reputation to engage with the close vote queue more.
- A third possibility is to petition SE to lower the threshold for closing questions from 5 votes (presumably to 3).
Stack Overflow did this, and while their queue remains very long, it did improve. Another 14 of the smaller SE sites (I don't have the list) have had this policy change. I gather they have had improvements as well. One thing to note about this option is that, if we elect to do this, it is unlikely that the change will be implemented very quickly; the SE staff who do this sort of thing has been reduced, even though the network has grown. Nonetheless, it can be done, if we choose to move forward.
Something to bear in mind is that we are discussing a very specific proposed change: Lowering the threshold for closing questions from 5 to 3 (I don't believe that even changing from 5 to 4 is an option). This change is on the table because it is something SE has decided they will do (eventually) for sites that want it. It may be that some other changes will come along with this (e.g., @StephanKolassa's observation that the number of close votes a user can cast was increased on SO), but even that is speculative. People have proffered lots of other ideas that may help if implemented in addition to or in place of changing the threshold, but those would ultimately have to be the subject of other discussions on meta.SE, approved by SE's hierarchy, assigned to developers' queues, etc. It is fine to spitball additional options here, but we need to be clear on what we're discussing and what changes are realistic.