Internet, less than 20 years old.
Electricity, most rural areas didn’t have it before the 40’s.
Water, been there since the beginning of time.
Food, livestock, been there done that, raised plenty of either.
Living in a major city or urban area, a guarenteed death sentence through starvation.
Feed the 8 million people of NYC through the bottlenecks of bridges and tunnels - what could go wrong. At least we have just in time inventory in stores (just like in so many NYC apartments), and what you see on the shelves is all they have. It's not like in one day the grocery shelves would look like our local gun stores, is it?