I also strongly doubt you can simply bootstrap a Netflix caliber development team, no matter how much you spend. I have no doubt that the people who came up with Disney+ had no concept of this.
Disney acquired a team for this, BAMtech, which had successfully run the infrastructure for MLB, HBO Now, WWE, among others. Certainly none of those were near as large as this, but they should have had the experience to know what works without needing to bootstrap.