I think there are many callings in the church that fall in the category of “unstructured” as opposed to “structured” leadership callings.
The unstructured ones have some general responsibilities assigned in the handbook, but in most cases, the bishop or other leaders are trying so hard to keep things going, and are so busy, they don’t provide guidance to the unstructured callings, and so the person called to that can do what they want, and in many cases is the least effort possible if no one is asking them to do more.
It is too bad, because teaching is a big part of church, and something we can definitely improve on. However, if it is not structured right, it ends up just being more meetings and adding little value. I guess it depends on the individual and their abilities, but it is easier for an Elder’s Quorum President who is given a list of things that must be done and is followedup on every PEC meeting, rather than an unstructured calling that no one provides guidance for or asks for followup on.