You're exactly right. We've even seen very small pre-seed companies (with just a handful of EC2s) throwing away a few thousand dollars annually in extra charges to AWS. The problem becomes even bigger at large companies.
If you could somehow automate this and provide a tool that did analysis of a companies aws stack usage over a month and suggest configuration changes that would be a big thing.
That's what Usage does - we aren't a consultancy to be clear. We automate all of our recommendations (and occasionally add a human layer above it)
That reminds me early stage startup’s betting big on Kubernetes