Why are only Suggested Edits quantities shown in the toolbar?

Question

In the toolbar, only the Suggested Edits queue quantity is shown. (I assume this because clicking on this number takes me directly to Suggested Edits every time.)

Why does this number only represent Suggested Edits and not all of the different review queues? Obviously, the close queue is always ridiculous (though that is getting better), so perhaps that one is worth excluding. But why are the rest not considered in this number?

If there is a disparity in mixing the different queue's totals, why show a number at all? Why not change it to some sort of icon notification if there are any review tasks available to be completed?

Answer 1

A pending suggested edit on a post locks the post against modifications by users without the edit privilege. It's in a partially-locked state for a large number of users. So it's important to get them resolved as fast as possible.

None of the other review queues have this level of urgency. The first posts and late answers queues show posts that bumped their thread so they're merely here to give more attention to posts that may warrant it, they don't block anything. Closing and deleting can wait a little because nothing urgent depends on it. Reopening is slightly more urgent as someone may be waiting to answer, but reopening often follows an edit which bumped the question and gave it more visibility. Suggested edits, in contrast, aren't strongly correlated with freshly bumped threads.

Answer 2

Primarily because that queue is much older. It was around for years before the other review queues were created. At the time this toolbar functionality was first created, the only queues were this and the 10k flag queue, both of which had their sizes in the toolbar.

It was also quite useful to have back then, as the edit queue tended to spend much of its time at or near the cap, so it was very useful for frequent reviewers to see if the queue was currently maxed out or if there was some remaining capacity there.

Once a bunch of other queues were added, not all that long ago, there was simply no compelling need to add additional notifications for them. Honestly, now that the edit queue is virtually always close to empty, it probably doesn't need to be there anymore either. I imagine it's mostly there just because people have come to expect it there and have gotten used to it.