I think you've been watching too much American Gotham
Cities are divided into areas, each area is 'supported' by council resources, by infrastructure, everything from access to hospitals and to schools to water supplies, rubbish removal and sewerage.
On the surface a city may appear to be one homogenous whole, but it's not, it's a group of areas that service their population and that interact with each other and support and are umbrella'd by the structure of the city. Business' of all varieties are an intrinsic part of that structure.
Removing people from their own area just causes huge displacement issues as they still need shelter, food, water, power, hospitals, schools, etc.,
There is flex within the individual areas, but none could take on the burden of the entirety of another.
Society is a multi-stranded thing. From the rural, who still use urban resources.....the vast majority do not live 'self sufficient' lifestyles. They don't grow their own wool and linen and spin and weave and sew their own clothing, for instance, but take that right across the board, from mining and smelting metal to making every dish in the house.....to those who are happily settled in the suburbs with access to both towns and countryside.
None of those people want to see society shatter, break down.
I don't think that's the topic of this thread though.
I think the topic is what can be done, practically, to mitigate any future issues that might crop up.
Just now there are two big issues.
One is the cost of fuel, and the second is the inflation causing prices to rise on everything from basic staples, to the stuff every household needs to replace.
There is also a third issue though, and that is the underlying one of a disease that's still killing people and how we must still be aware that it might evolve into something less infectious but that it might evolve into something very much more severe.