A lot of those things have expiration dates.

Medicine loses potency or goes bad over time. Ammo can get moisture in it or just become unreliable over time. The lining in food and drink containers from most things in the grocery store will usually break down or begin to in about a year and start to leach into the food. Fuel to power any generator will go bad in six months, unless you use additives for long storage and those can cause an engine to be running lean or richer than it should be. Guns need replacement parts and won’t typically work forever with some TLC and the ability to fabricate or just have parts stockpiled

Basically most accelerationist plans for the apocalypse are not backed up by any sustainability. Things like ethanol production and a good battery bank system would be far more sustainable than the usual type of stuff that I see them preparing for. Not that guns couldn’t help, it’s just that if you don’t know anything else and can’t contribute to keeping yourself alive for longer than a few months or a year then that’s just going to end up with sick and starving gun nuts who are desperate if they survive that long