Why it disappears from services quietly
Nobody complains about high-level dust until it becomes visible, which takes a long time and then arrives as a large problem. In the meantime a task that is difficult, requires access equipment and takes a cleaner out of their normal routine has every incentive to slip a cycle, and then another. There is no feedback loop, and without one the task erodes without any decision having been made by anybody. Erosion without a decision is the characteristic failure of every invisible task.
The consequences appear elsewhere. Dust from ledges, ducts and light fittings falls onto surfaces below, which shows up as a general complaint that the offices are dusty despite being cleaned. The cleaner is then asked to work harder on the desks, which does not address the cause at all. Diagnosing that correctly usually means looking up rather than at the surfaces being complained about. Looking up is not the instinctive response to a complaint about desks, which is why it is often missed.
