It does seem to me a part of the solution needs to be helping to get those patches reviewed. I don't know how to do that, but perhaps there's a way to encourage people to review more stuff, or review stuff from a wider range of contributors. Say by treating reviews more like proper contributions.
This is a huge problem. I've been in the situation before where I had some cycles to do a review, but actually finding one to review is super-difficult. You simply cannot tell without clicking on the link and wading through the email thread. Granted, it's easy as an occasional reviewer to simply disregard potential patches if the email thread is over a certain size, but it's still a lot of work. Having some sort of summary/status field would be great, even if not everything was labelled. It would also be nice if simpler patches were NOT picked up by experienced hackers, as we want to encourage new/inexperienced people, and having some "easy to review" patches available will help people gain confidence and grow.
Long time ago there was a "rule" that people submitting patches are expected to do reviews. Perhaps we should be more strict this.
Big -1. How would we even be more strict about this? Public shaming? Withholding a commit?