To give an answer; Yes for some and no for others. (As told in my comment, except new post, other queue seem ok)

For me we seem to loose old contributor, while we cant much get new users to help there, but there is a fact that does not help us;

Something that I hate is the fact that MSE seem to have dropped the ball for the review queue for mobile user. As for me I mostly use the site on my mobile phone, and MSE never integrated that feature there (https://meta.stackexchange.com/questions/148616/review-option-on-mobile-phone-not-available)

Giving a well documented answer is hard on the mobile app, but reviewing would be an easy task, thus I think MSE don't help to get new reviewer.

There is a output, you see the mobile site usage, as almost %50 ... so MSE seem to have miss the boat there.

[![enter image description here][1]][1]


  [1]: https://i.sstatic.net/1zc1o.png