Tons of times in the past 100 years or so there have been periods of shortages, wars, weather & earth events, financial depressions and so on. In the past 30 years I have endured plenty of weather events like hurricanes, floods, massive snowstorms and then financial debacles like 2008 and Covid. Covid we had bare shelves at times. I'll never forget in April 2020 a load of paper towels being set out in a store and people acting like complete maniacs tearing into it. There were various shortages of things for about 2 years after coronacon kicked off.
The debate on prepping to me is like the financial debate over whether to sink money into assets or things that generate cash flow. In other words whether you trade or invest, it's two different things. Ammo is a great example, sure you can buy tons of factory ammo but also why not give yourself the ability to generate your own ammo and reuse your brass by having reloading equipment on hand with components so you can always make your own?
So the approach I have taken is have some stuff on hand, fuel, food, ammo, paper products, health products, etc. but also try to have some ability to generate my own stuff to survive if need be.