This is cool and it's always smart to check past implementations like this. As long as you learn why the failed not that the idea is impossible. VR is a good example; I didn't see any companies on that list but many gave up on VR because it was too early to be possible until a few years ago. Another good example is digital currency.
Also; you can learn from a comp like Clinkle which should def be added to the list
Also; you can learn from a comp like Clinkle which should def be added to the list