If the difference between preparation and panic is largely one of timing, the difference between sensible precaution and paranoid prepping is only one of scale.
And I think you're perfectly right - the pandemic has reminded people that we can't necessarily *always* rely on *everything* being available *all* the time.
As we've seen, there are many potential situations well short of a zombie-apocalypse scenario where shortages become a distinct inconvenience, even if not a critically threatening problem.
The other aspect to consider is economic confidence. If people are worrying about their jobs and future income, they may be inclined to sink some money into toilet paper, pasta and cans of soup while they still have it.