Prepping and Mustaschianism probably have a large overlap. My husband and I have engaged in this to a very small degree - we reviewed the CDC preparedness guidelines and have all of our important documents in order in case we need to evacuate. We also have a few gallons of water, a first aid kit, and other supplies in case of an emergency. But living in a small apartment in a residential neighborhood of NYC, there's not much else we can do.
Today I learned about the Bug Out Vehicle. It's a car or truck purchased for the purpose of escaping one's surroundings during a disaster. It's a bit much, don't you think? ;)
There's really not much else you can do. It's wise to have supplies and a plan for a short-term emergency, up to a week. Say a hurricane (or earthquake) knocks out transportation, power, etc and you have to wait out rescue for a few days. This is the most likely scenario, not unheard of in modern times, yet still rare. And it's relatively cheap and efficient to plan for. We are in earthquake country so we keep some emergency supplies on hand: water, first aid, food. It helps that I do a lot of backpacking/camping, so some of this stuff overlaps, also means we have gear for treating water and portable stoves and shelters.
IMO the entire premise of prepping is flawed, mostly based on urbanite wilderness survival fantasies. Assuming you could even escape the city you're not going to live long-term in the wilderness with a gun, knife, and a few other supplies. When I'm out backpacking and/or hunting I'm always struck by how lean it is. Even in the best of times, the height of the summer growing season, food is relatively scarce and difficult to find and even harder to get. And this is with hunting and fishing being highly regulated. In a prepper scenario social order would totally break down. Wildlife would quickly be decimated, maybe not to the point of extinction, but certainly to the point that it's no longer a viable food source. If you have a huge stash of food/supplies somewhere, what's to keep someone from taking it by force? In a state of complete anarchy strongmen/gangs would quickly take over, only the most violent, powerful, and organized would survive. Your shit will be stolen, you will become a slave to the most violent gangs (labor and/or sex). This is not novel, we see this in every area of the world where social order breaks down.
TL;DR - For prepping to work you have to go all in now and orient your entire life around being ready to take power if the need arises. But doing so means you have to live a pretty miserable life in anticipation of an extremely unlikely future event. Even if you do everything right you're not likely to survive, and even if you survive it will only be because you were willing to be more violent and aggressive than those around you. Meh, I'd rather just be done with life at that point.