Interesting. I save all (or almost all) shoe boxes. At any time, I may have about half or less of my shoes out on the rack and the rest are stored in shoeboxes in the closets.
For example, right now there is no point in keeping pumps, sandals, hiking boots or even lightweight fall shoes out in the open - we have snow on the ground about waist-high. So they are put away, and many are stored in the original boxes to make them easier to identify. The only out-of-season shoes that are not hidden away are those that I keep at work to change into - I store them in a large box under my office desk.