If I had the money to bet, I'd be betting on AR as the next major paradigm, though. I think the idea of OS changes a lot when you get rid of the "slab of glass with a terminal" model. If computers are fundamentally ubiquitous, then what an OS does will need to be quite a bit different. I'm not sure it replaces a legacy computer, but I genuinely hope to have AR be a completely alternative option for most applications.
If I had to guess where the funding for that salesforce will come from, I'd guess: Softbank, and other mega-VC funds. if you do successfully create the next wave forward for computing, and you can provide the systems to enable it, the rewards are likely commensurate. I think this is why everyone is so interested in AR. Magic Leap is the darling, but Google, Apple, and Microsoft all agree that this is a critical turn, and are putting in the dollars to win.
iOS is NextStep, and Android is Linux, so in that way what Steve said holds true, given that Linux wasn't developed commercially.
It's amazing how well this insight/prediction holds after 26 years, the only other comparable OS/OE today is linux, which didn't rely on the funding. Makes me think if/how another leap in computing software will happen.