Let me help you out with a more broader perspective than what you've given such technology that transcends glasses, headsets, and glasses-free spatial displays:
Spatial computing by eliminating the constraints of physical screens enables a myriad of contextual, hands-free computing, immersive, and multi-tasking computing be significantly enhanced and more efficiently done through it than traditional computing.
Your email example is a perfect example. Instead of doing so on cramped 14"-16" screen, you can do so far more efficiently and with infinitely more canvas space spatially in addition to a multiple of apps placed not only vertically and horizontally better placed but spatially forward and backwards.
Instead of the limitations of having to hope that a rollable OLED ultrawide and ultra-vertical monitor that can go from 16:9 to 21:9 to 32:9 and so on to come out (and so on vertically), you can do so with spatial computing hardware like the Vision Pro.
Premium and emerging content like film in their native aspect ratios and vertical video will always be more fluidly represented on a spatial computing device.
All things equal, spatial representation of video and photos is the superior, ideal representation of video and photos; to best represent such things will necessitate spatial computing devices.
Spatial computing overall allows people's relationship with technology to be rethought to be more seamless, enhanced, comfortable, and more contextually helpful.
This is how throughout computer science history the pursuit of spatial computing has always justified spatial computing devices.
For the most immersive spatial computing experience–even as mindless as first-person games–VR technology by necessity will be the best means to accommodate such computing use cases individually.
I hope that helps you understand why VR isn't going anywhere besides average technologists pushing back on costs and the lack of choice of being able to have similar quality of a Vision Pro and other high-end spatial computing devices in form factors such as glasses and spatial monitors.
Both of those form factors necessitate far higher costs than the Vision Pro today that the average person is not well-versed on the technology constraints that necessitate that (or understandably care).