This is a peak HN comment (the one you are replying to)! The other day on the Wikipedia thread, there was a data scientist who said he could run a website like Wikipedia all by himself. "How hard it is?". And here we have the same thing for Amazon..
Admittedly I've even heard senior executives rhetorically ask "What do all those people at $LOCATION even do?" At scale, you need a lot to sell, support customers, put marketing programs in place, do developer outreach, test, be on call, etc. etc. But, yeah, you'd think it would obvious that even just talking about straight engineering, you need more than a fraction of a person to develop and enhance each AWS service.
AWS have close to 200 services. If the origina cmmenter js saying each service has 50 folks, it is 10k people. Which sounds about right the company have more than a million people working across all sub organizations. So you can imagine all kinds of work environments