Companies have no incentive to employ as many people as possible. Really it’s the opposite, make as much money as possible, while paying as few employees as possible.
That is the incentive to employee more people - they can do more with those people. There is a balance between the two though. More people means less focus.
The incentive many times is to create a scarcity of talent for other tech companies by hiring as many experts as you can. Facebook, Amazon, and many others have been employing this strategy for over a decade, but now that the era of cheap money is over we're seeing a pivot away.
