When SHTF, a lot of folks here may be stocked to the hilt with canned foods, buckets of dried foods, rice, etc. when shit really begins to hit the fan there are a few major reasons why you should steer clear of your stockpile for as long as possible:
# 1
If it gets to the point where do you feel compelled to start consuming your prep, then that means things are likely not gonna be getting better for a very long time, which means that you should be out there in the streets/stores groveling for whatever remaining supplies you can get, and continuing to stockpile excess while reducing your consumption to subsistence levels.
By the time that available supply runs out, everybody who has no prep will perish (this is not a good thing - don't celebrate the demise of others, just because they were too ignorant to prepare). After this period of time passes, there will be a lot fewer remaining people to consume whatever resources remain, which means that you may not have to dip into your stockpile to survive. If things continue downwards from this point (think of a worst case scenario like a nuclear winter), you will still have whatever number of months of supplies that you started with to survive the real SHTF that ensues.
Reason # 1 could be summed up as "shit can always get much worse".
# 2
The next reason is that you may think shit has hit the fan, and so you begin to consume your stockpile, and then suddenly things turn around and start getting better, and now you have consumed your stock pile and you are no longer prepared for whatever comes next, while the likelihood of another SHTF scenario probably increases exponentially after this point in time (due to all the systems that will have failed as a result of the first SHTF).
# 3
If your neighbors and everybody around you have been going to the store/other resource pool, and you have just been comfortably hiding out in your house (to avoid chaos, etc.), then the likelihood of somebody nearby realizing that you are stocked up goes up increases.
The first point stands on its own and should be reason enough to follow this advice.
BONUS
Whatever food preps you have, add 100 pounds of rice AND 1 water filter (life straw or Sawyer Mini) per person to that. It's cheap AF, you can buy cheap mylar bags from Amazon and oxygen absorbers to put in those bags and the race will last for many years. And then you will have about six months extra runway when SHTF.
Here are the mylar bags:
https://www.amazon.com/dp/B08MDWBMY4/
Here are the oxygen absorbers:
Berkey is just a giant Britta filter - literally a gravity percolator through activated carbon and ion exchange resin. I've got better shit on my fish tank. It's overpriced shit.
That doesn't match the independent lab tests on Berkey filters. Do you have other tests that prove otherwise? If you have sources to prove me wrong, I'd be happy to read them.
There are industry standards to test to, and yet they refuse to actually test to those standards. Their independent lab tests sent a single gallon through the filter before testing the output. NSF/ANSI standards require twice the rated lifetime capacity to go through the filter before testing its output. Moreover, they make ridiculous claims that they get 99.99999% of contaminants out, which is orders of magnitude better than distillation and reverse osmosis, the best filtration methods there are. A pretty bold claim for a company that refuses to subject their products to industry standard tests. People have cut open black Berkey filters to reveal the insides, and it's literally the same shit that's in a Britta filter: compacted activated carbon and ion exchange resin.
If you want 99+% purification, get a RO system. You can even combine RO with carbon and ion exchange resin to get really pure water.