“major studios do use some cloud services” is not the issue. The problem being addressed is that the “script to screen” process is typically an antiquated mishmash of offline-first vendors. Netflix reinvented that with a cloud-first process.
“Digital-first production” can mean lots of things, so when you say Disney, Paramount, etc did this a decade ago, you’ll have to be more specific. Do you mean an end to end digital process? That’s not what this is about. Have you worked on a Netflix production? It’s night and day different from the studios you mentioned.