Why do they keep trying it?
BBC
announced that it's abandoning expensive and audience-less 3D video.
Why in the hell do they keep trying 3D?
The concept was invented, needless to say, by Wheatstone in 1830.
Every concept that has the slightest connection to symmetry or two-sided-ness was developed by Wheatstone in 1830.
Stereoscopic stills were hugely popular in the late 1800s, and the idea was applied to movies as soon as movies became somewhat commercial. It failed.
Repeat about a dozen times, through the 20th century with film and into the 21st century with digital video. Tried it, spent huge amounts of money, failed. Tried, spent, failed. Over and over.
The basic problem goes beyond technology, and I doubt it will ever be solved by technology.
When we move through the real world, our brain uses all sorts of cues and templates, immediate and remembered, to build a picture of our surroundings. The immediate focus of the eyes is just one element, and probably not the most important. The old stereoscope worked fairly well because the gadget forced you to focus on one fixed point and gave your eyes time to adjust. With a movie you don't have the real-world cues, you can't force the viewer to focus on a single point, and 1/24 second isn't enough time to adjust.
= = = = =
Historical sidenote: Modern tech types would do well to read
this 1856 book on Stereoscopes by David Brewster. He understood the variability and limits of binocular vision in a strictly experimental way, and developed several simple solutions to the problem.