How often do you vacuum ceiling/walls
I've been asked to vacuum both ceiling and walls when doing general house cleaning (my home, but run by my wife). I would argue that vacuuming ceiling/walls is a "spring cleaning" task, maybe even wash the walls and trim, but not something done every week, or even every two weeks.
I think our home is typical as regards the infiltration of dust. Dust does accumulate on the furniture flat surfaces in one week, but I think very little is on the walls and ceiling due to the passage of one week.