Just my perspective as an active elder...
When I attended the elders school in November , the average age must have been 55 , including numerous very old brothers. There were some younger elders who did the bulk of the teaching parts. Notably , there were very few "young" (30 something) elders - and a couple of them had "goatee" beards , so I guess the appointment criteria has been relaxed!
One of my fellow elders gave a talk at the MS KM school on the Sunday and he was saddened that most of the servants were the kindly , elderly type with very few who would be likely to be potential elder material. To make matters worse , in the UK , the WTS is expanding in Bethel and is cherry picking many of the young , enthusiastic brothers without any thought of the effect on their home congregations.
The CO is desperate to appoint any brothers , regardless of qualifications. A couple of years ago , the body was split 50-50 on appointing a certain brother as a MS (I was strongly against an appointment) and the CO forced it through - we are now left with a brother as a MS who hardly attends meetings , has no responsibilities whatsoever and is a MS in name only.
Without giving too many details that would identify my congregation , the elders carry out virtually all the functions that normally MS would have carried out , due to a combination of lack of manpower and lack of competence from our servants (none of whom would be given a recommendation if they moved away from here.)
Just my 2p.