The great part about preparedness planning is there is a kind of vaccination herd immunity effect at play. The more people who take minimal measures like you list, the less intensive efforts preparedness-minded have to invest into. To your example, if 90%+ drivers keep a flat of bottled water, then it makes sense to only keep a water filter at one's home instead of one in the car for long trips and one at home.

However, Just In Time doesn't just permeate our supply chains, but many people's personal lives. So the lists of what it takes to ride out life's inevitable curve balls grow ever longer.