[Sayrus]

Setting up a database, backup processes, object storage, archiving, and especially compliance is a huge upfront cost for a small company.

It is true that you pay for the engineering done by AWS, but you also need to take into account the network effect and compatibility with third-parties.

With this being said, AWS is still very expensive. But AWS being profitable doesn't imply it is profitable for you to run your own infrastructure. The same way it is not profitable for you to run your own shipping company, or your own internet backbone provider.

[bananaquant]

Indeed, that is decided on a case-by-case basis. So if a company determines that moving on-premise is cheaper than AWS, perhaps that is actually true for them.