As to OP's comments (good comments BTW),
Minimum wage workers should come back in time.. Why work with so much stimulus out there? Working could be negative $EV these days
Not quite the same with box supplies but I'd guess it's mostly short-term bottlenecks. See Lumber... Zero business, shut down, maybe liquidate inventor to satisfy lenders and APay... A year later, big surge, no inventory.. 12-18 months last, normal inventory.
Or maybe I'm completely wrong