I respectfully disagree. There's a sweet spot where companies can use the lowest foundational building blocks, build their own stacks on top, and save resource

I respectfully disagree. There's a sweet spot where companies can use the lowest foundational building blocks, build their own stacks on top, and save resources (comparatively to running your own datacenter). Things like EC2, EKS, S3, and RDS Aurora can be considered foundational but you don't really have to use Athena, CloudWatch, or RedShift (they are super expensive anyway).