I mean preppers are mostly cosplayers and I don't criticize people who go to comicon either. If you're not hurting anyone there's nothing wrong with having an unrealistic hobby or one without a lot of practical utility (even if the premise of the hobby is having practical utility).

But the western Roman empire fell and cities depopulated and folks switched back to subsistence farming for hundreds of years.

And plenty of places have been at war and had much of civilization's usefulness diminished from days to decades. Not to mention straightforward natural disasters.

My prepping is limited to buying toilet paper at costco and having bags of beans and rice and such in my pantry and just... knowing how to do things in general.