It's been hovering around 50k for months now. I'll give the benefit of the doubt and assume these questions are well-prioritized so that the totally irrelevant-to-close questions according to some business logic. (Note: I'm not sure if this is true.)
Anyway, here's why I think this is an active problem: Reviewing closes is an extraordinarily thankless task at the moment. I put in my 1k for the gold badge a while ago - mostly on the very quick "off topic" votes - and thanks to my work the queue has gone from 50.8k to 50.6k. For me to continue working on this problem, there is no rep, no badge, and no impact on queue size. That last one is literal - 50 a day leads to 10 questions closed on close votes, and that isn't a significant digit in the number "50.6k".
So the goliath queue means people like me, who like getting s*** done and seeing empty lists of things to do and such, are rather actively deterred. I suspect this queue would move much faster if at any given time it were limited to 1000 and some offline task sneakily added more work to a few hours after it reaches bottom.
No concrete proposal yet. Everything I can think of is kind of "eh," and I'd rather this question over some chance for momentum than amass downvotes based on my poor solution set thus far.