The diminishing number of AMEs is largely the result of the incompetence of the CAA management who presumed to dump all their responsibilities onto the AMEs whilst closing down the CAA Medical Dept to save money.
My AME, who I have know for 40 years, said a few years ago that he had no intention of stopping. At the last Medical he said "I have had enough, I don't know who to recommend because many more are quitting for the same reason".