The primary problem is that the Apple Vision Pro currently is an entertainment device priced like a mid to high end workstation. But even with zero additional content, there's a price where it becomes worthwhile just to watch movies on.
I'm hugely critical of the AVP, v1 is a flop (and least by Apple's standards) and won't see a redemption arc before it's discontinued. The next pro version is going to need to learn a lot of lessons from their low end headset. What I'm not though, is blindly critical... I've used devices in this space, and see plenty of reasons for optimism. Price solves a lot more than you give it credit for.
A stripped down device without the cost, weight and complexity of Eyesight and maybe even a plastic casing would dramatically improve the ergonomics of the headset. I'm not going to make any assumptions that Apple will ever figure gaming out (they simply refuse to), but they will eventually unlock fitness. I've done plenty of workouts on the Quest (until my health got in the way a regular workout routine). Fitness, movies, tethering to a Mac, the iOS app library (especially messaging apps), and the spatial OS that is VisionOS would absolutely move units at a sub $2000 price (I'd love $999 like I mentioned before, but it's Apple...), even if they have to sacrifice some visual fidelity to get there. Developers would be on board with a sufficient user base to address the much of the content problem you mention (caveat on the Pro version below). While you're right that most people won't use these all day until ergonomics are dramatically improved, but that's not pre-requisite for finding some success in this market, it just puts a ceiling on price.
Price doesn't solve everything, especially with the Pro version, because there's only so low that Apple will go there. If Apple wants to sell a $3000+ Pro version they will need to be doing some heavy app development lifting themselves and reimagine all their creative apps for best use on this platform. That or straight up turn it into a Mac that's also wearable. I'm with you on the content problem on this front, but not on a cheaper device. Apple has the pieces, it's just a question if they put it together.