I know of AWS's reputation as a business and what the devs say who work there, so I have no argument against your point, except to say that they do manage to make it work. Somewhere in there must be some unsung heroes keeping the whole thing online.

The point being that AWS runs AWS, they don't run your business on AWS. You still need someone to actually set up AWS to do what you want, much like you would need someone to run your on-premises servers. And in my experience, the difference is not much.