Well, display hardware isn't the problem. 4K, 8K, there's no end to it. Cascaded displays using multiplied layers seem to help achieve benefits like sharpness at super high resolutions & effectively smoother results at low frames per second (staggered) video playback. This helps remove a major obstacle that high-res display technologies will face in the short term, which is processing power. Presently, high-end graphics cards can barely crank out 30 FPS at 4K resolutions for games. Also, any compression artifacts etc. in textures are much more pronounced on high-res/big sized displays. While requiring the need to change the workflow (of game development) a little bit, cascaded displays can potentially help render higher resolution, better quality/sharper images at lower frame-rates (i.e. much more cheaply) while still providing that 60fps feel.

Personally, if this takes off, I can see it saving the XBox One's ass, as a lot of the complaints from gamers have been regarding it's inferior capabilities for rendering high-end games (It renders many games at 720p 30 frames/second, while Playstation 4 is able to crank out 1080p for the same titles), and also, play another factor in prolonging the shelf life of the present generation of consoles, by enabling them to deliver much better graphics with the same hardware. Kind of like what Normal Maps (among other things) did for Xbox 360 & PS3, you can see the difference in graphics between a game released in 2005 vs a game released in 2013 on the same hardware. Among a lot of other factors, that was why it took 7 years before we saw the next generation of consoles being released. Comparatively, the Xbox 360 came out within 4 years of the release of the original Xbox.

TL;DR - It's not about the display hardware itself, it's about the ease of rendering graphics to meet the demands of high-end display.