First, not everyone, possibly not even a majority of people even in the US, can necessarily afford to set aside the price of a months supplies for the family. Many families are two paychecks away from living in their car. They are entirely too busy keeping a roof over their head and food on the table to spend much time worrying about hypothetical situations. I know and have worked with people whose entire discretionary budget for their family, assuming nothing goes wrong, was ten dollars a week.

That doesn't mean some level of preparedness isn't possible. A few dollars a week can be built into a substantial supply. At least it might if people don't get discouraged and give up before they get a start.

The three-day standard was selected to be a small enough step to be reasonably easy to accomplish with limited means but large enough to make a significant difference in the majority of situations in the US.

In my opinion, based on what I see in various reports, the distribution of supplies is being hampered by a desire to control the situation too much. They are handing out rations very slowly to thin lines of people when they should, IMHO, be taking their clue from feeding chickens instead of running a soup kitchen. We should be shoveling individual foil wrapped water packets and lifeboat biscuits out of the back of helicopters and trucks with feed scoops. The actual form of the relief is not important as long as they come in durable packages and a small number of servings. Single-serving size would be ideal.

Find people and spread supplies while moving. No stopping. No demand for anyone to line up. Wash, rinse, repeat until nearly everyone has received something. If the vast majority of people can get a little to eat and enough moisture in them so they aren't in danger of falling down your going to calm everything down considerably.

Take the edge off and then set up the more organized systems with lines and controls.