I agree with the basic premise and math here but getting to true 24/7 uptime in the cloud will require a minimum of 2 full time cloud engineers or infra people. If you're spending another 500K in usage costs you're almost at a million. For most, the cloud is the right option because maintaining servers is a pain and modern clouds offer a lot of additional features that may be useful, but it doesn't mean it's a massive win for the bottom line. There are lots of small and large companies that could run servers on prem or in their own datacenter and it would make financial sense, but they'd have to attract the talent to build and operate, which is harder than just paying enough.