What you do, if you're a VC backed SaaS company with a six or seven figure monthly spend on AWS, is hire away someone from Netflix who does know what their discount is and use that when your next contract negotiation is up with AWS.
“I know this is possible because we had it at X” is a lot different conversation than “We want X”. Your leverage is even worse when X is nowhere near reality (in either direction).
There are EC2 plans as well, which I assume means that you can get discounts off the reserved instance pricing - but you'd have to ask your AWS rep about that.
If you spend > 4 figures on an AWS service you should ask for their discount plan. Nobody wants to say what they get discounted on, because they might lose them (and the contracts are confidential). So you have to ask your rep.
On the other hand, just read this disclosure in the Netflix 2023 annual financial report: "We have architected our software and computer systems so as to utilize data processing, storage capabilities and other services provided by AWS... Given this, along with the fact that we cannot easily switch our AWS operations to another cloud provider, any disruption of or interference with our use of AWS would impact our operations and our business would be adversely impacted. While the retail side of Amazon competes with us, we do not believe that Amazon will use the AWS operation in such a manner as to gain competitive advantage against our service, although if it were to do so it could harm our business."