Things are significantly more just in time than they were then. Companies hold debt, minimize cash, and minimize inventory, optimizing for efficiency and not robustness and this is an event well outside the likely operating parameters of even the most conservative and careful finance teams.
My grandparents used to do their shopping monthly, they had a store room, they had a crazy amount of food. Until recently I went shopping a couple times a week.
Companies have been doing a similar thing -- once all the inventory is gone, the cash has paid salaries and you can't get a loan to rebuy (your suppliers are in a similar boat anyway) what do you even do? That's going to be the issue with getting things rolling again if this goes on long enough to kill off a large percentage. Right now, the weakest/newest companies are being culled and people arent really noticing - the BKs will get bigger with each passing week - most companies just aren't set up to run like this and starting back up could be a challenge. (I fully expect another massive stimulus/SBA program to be needed after a solution to this exists, I think they shot their shot on companies too early and should have focused on individual relief and just allowed the normal debt/BK cycle to play out - were just making the bubble a bit bigger in my opinion).