> Most objects aren't moving that much. [citation needed]. Even just one object moving from one end of an axis to the other end would incur catastrophic slowdo

> Most objects aren't moving that much. [citation needed]. Even just one object moving from one end of an axis to the other end would incur catastrophic slowdown, and depending on what you are simulating, this might occur regularly (for example, consider teleporters in a video game). When that happens, you incur the full O(n^2) iterations until the axis is sorted again, even though only one object is actually out of order. There are certainly simulations where this approach is fine (if you can be absolutely confident that no object ever "skips" around, like when you're running a simulation that is configured with an explicit upper bound on velocity), but I think that this still requires this warning label.