To paraphrase The Economist, "This device is amazing, and now Apple needs developers to figure out what it's for." https://www.economist.com/business/2023/06/06/apples-vision-...
I’ve never seen an AR/VR usecase that interested me, but if this thing turns out to be a decent replacement for external monitors I’d probably buy one. I travel a lot for work and the laptop on the shitty hotel desk setup is a major drag.
It is conceivable that completely different categories of workflows will become available. In the end everything we do on a computer has been invented at some point or another. I guess there are plenty of eager early-adopters and fanboys that will be more than happy to report on their magical productivity boosts.
In any case, assuming that the above caveat is not an issue, if the main real use case is as external monitor replacement I would think that suitably optimized hardware would deliver much better value for money. No need to wear a computer on your head when you need to carry one on your laptop (even mobile) anyway.