[tylerdurden91]

To the contrary, from my time at Amazon, I felt that developers want to use more high level AWS services. Unfortunately, the landscape of AWS services is so rapidly evolving that Amazon engineers themselves cant keep up and end up using the wrong service.

As mentioned in other comments, there are options such as Fargate, that would still technically be "serverless" and still yield similar cost reductions. Not to mention that AWS also has Step functions express for "on host orchestration" use cases. This seems like a case where the original architecture wasn't very well researched and nor was the new one.