Not disagreeing with your point, but it's important for a new project to consider the human cost of ops in addition to the cost per request.

Lots of "enterprise" solutions don't need more than a few hundred TPS and can tolerate some of the variability that comes with lambda. The net cost (including ops work) will likely be less in these scenarios, plus they don't have to staff for a devops guy or pay to build that skillset up internally.