What's not to understand that when you're having to spend 4.85B in order to get 5B in revenue makes your business quite risky. You want to be operating on larger margins than that
Pretty normal margin in some kinds of businesses, like supermarkets. Then again, supermarkets aren’t likely to see all their customers leave at the drop of a hat.
The scale is also very different. Costco earned $70.53 billion in a recent quarter (not 5B here). Their operating margin is 3.93%, which is also healthier.