I have to say, you're completely overlooking why AWS/GCP/Azure are good services in your answer. The value add from using these services is that you don't have to know how to run any of these things, building an SRE/devops/sysadmin organization is non trivial for a team of developers with a background in application development. Spending an extra 100k a year on AWS is likely cheaper than the cost of building out a team to do all of these things for you, including as things scale.

If you're going to have a team of people deploying all of your own middleware software anyways on VMs, that completely defeats the cost savings from using cloud these days. It's much more of a PaaS business than a pure IaaS one.