Earlier quoted context omitted.
But if it were accurate, wouldn't companies spend more effort on retention and engagement over hiring? This is a data point that I have seen claimed for years and years and yet companies don't act on it. Companies are either making a near universal error that has been well publicized at this point or the number is wrong and hiring is nowhere near that expensive. Amazon is a very data driven company. But they have no…
It's an average, not a universal. Confronted with the data, you COULD choose to increase engagement, or look to reduce cost of churn. Amazon delays equity a lot, so it may look financially sensible to churn through people. Beyond that though, companies make plenty of universal errors. Can you think of any other errors the -average- company makes, that may cost them money?
I can see equity being a reason for Amazon, but it is hardly just equity granting companies that are this way.