> but that doesn't prove they'll eventually succeed
Of course it doesn't prove anything. But there's certainly a difference between the "hardness" of designing sufficiently high quality 3D glasses using well known technology, and doing something that breaks a physical law.
My point with perpetual motion machines isn't that good VR violates physical laws. It's that some ideas are attractive enough that people will keep trying and failing to make them real, without bothering to look at why the other attempts failed.
My impression is that even 2D screens are still rather lacking (they're big, heavy, very bright, need a big power source, rather expensive, sometimes difficult to interact with). In many situations a book or some papers are still superior to "virtual 2D reality".
Not sure if this indicates VR is conceptually flawed or if it means we're just still early in the development of the technology.
In my opinion, the other attempts happened because people think 3D is cool. Both as a concept and as a novel experience. And the other attempts failed because they went out and built a lot of stuff based on that coolness, without testing to see whether there was lasting value.
And we certainly see that repeating here. Magic Leap burned $3.5 billion. I'm not sure how many tens of billions Meta has spent on their vision of a Metaverse. But what's pretty clear is that so far there's very little long-term usage, very little value creation.
Might it work someday? Sure. But it's perfectly plausible that it will remain a practical failure until something like the holodeck or programmable matter becomes a reality. So it could be another 170 years before VR is a success.
Of course it doesn't prove anything. But there's certainly a difference between the "hardness" of designing sufficiently high quality 3D glasses using well known technology, and doing something that breaks a physical law.