I don't agree here. There's the economy as we know it, which might crash/malfunction but then there is the Real Life™. It might seem that the two are very interconnected and society cannot function without a healthy banking system. Reality however proves different.

Let's take a look at Iran, a country under heavy financial and commercial sanctions (for quite a few years), partially at war, with widespread riots brewing up until just one month ago and with little control over the virus's spread. Life goes on, people still eat, speak to each other and most continue their day to day activities. Same goes for Venezuela or Lebanon.

Sure, some people will need to adjust from selling derivatives to more 'core' activities, but the world will not end. The social system is more resilient than it looks.

EDIT

From a longer-term/big picture point of view, I think it would be healthy to debunk this 'myth' that somehow the world cannot survive a big bank going bust. Let's not mistake preserving status quo for a functioning society as a way going forward.