You are looking at it from the opposite perspective that comment is addressing. He is addressing people who think companies can still be profitable with less people. The goal of the company is not just to be profitable.

> Seems obvious? Can you name a company that thrives by hiring employees that add less value than they are paid?

That’s not the part that gives insight to the question “how can it take X engineers to run service Y?” The insight is that employees can add more value than they cost even if they aren’t working on the most visible core product that the company is known for.