> So what happens if the Vision Pro becomes the best interface to general-purpose computing
this is exactly my fear
The people who present Android vs iOS as a matter of personal choice are being slightly disingenuous. They are pretending that this choice is a natural inevitable result and will always exist. Their whole reasoning that iOS is "ok" is based on the fact that Android - another totally independent ecosystem, exists. And let's not forget, it's one which Steve Jobs vowed to sue out of existence.
The "android" of that ecosystem is the Meta Quest devices. At the moment, yes, you can sideload there and Zuckerberg is on the record saying he will maintain an open ecosystem. Yet it's still very tenuous. The sideloading experience is very poor, worse than Android (something you sideload can't appear as a first class citizen on the device - there's no way to have it show up in the main app menu, random permissions don't work sometimes etc). And the Quest OS layer is not open source - only the underlying Android OS.
The technical hurdles required for VR/AR are much bigger than general computing. It's not at all clear to me that an open alternative will emerge. So we are potentially headed into an era where effectively there's no option for general computing that isn't locked down and owned by a Mega corporation. And all these iOS users who are preaching tolerance of Apple's approach will have been the key enablers of this dystopia.