You seem to think not having a killer application is an option. Macintosh didn't really pick up any steam until a year or so later when desktop publishing became its killer app, when Steve Jobs revived Apple besides having laser focused hardware, they had to deliver Mac OS X and make it indispensable, along with showing clear advantages of using certain programs like Photoshop that were incredibly vital to Macintosh's health, iPod the killer app simply was it stored a lot of music in a small space when that wasn't the norm, the iPhone the multi-touch along with how the iPod, phone, and internet worked (and later the App Store and the world changing apps that came out of that), the iPad it was its ability at first to be the best way to consume digital media and later great apps like Procreate combined with the Apple Pencil that makes it indispensable, the watch was the health apps, so any new product category needs these things.
I don't know at this point what the killer app for Vision could be as from what it looks like now, it's just a really nice iPad that straps to your face. I figure it has about a year tops to find it's "killer app" or else it will just be another AR/VR thing, but hey at least people can play Beat Saber in crisp 4K now.
Which funny enough, I think would be the best selling app on the thing, just as Beat Saber has been the best selling app on any modern VR headset. Beat Games could even work with Apple to perhaps incorporate Apple Health stuff and Apple Music stuff into it. That kind of stuff would be fantastic. That's actually the best idea I've heard for this thing! I should be a developer. I can update a 5 year old app that runs just fine on $200 headsets and comes free with most of them, and charge $20 for it and all people have to pay is $4000 to try it out. Brilliant!