What is the future of Ultra-High Definition(4k/2160P) blu-ray??

[Vinther1991]

4K UHD Blu-Ray is to movies what PS4 Pro, Xbox Scorpio and high-end PCs are to gaming. It's for those who want the greatest visual and audio quality from their movies/games. For them the small increase in quality is worth the upgrade. It's probably not a big market, but it will survive no doubt, even if it's only 4k blu-ray collectors who buy them. Those who claim it doesn't have a future has to question the chances of success for the PS4 Pro and Xbox Scorpio and the future of physical media for games as well.
For huge film buffs like myself, there simply isn't a better alternative to physical media. The library of movies available to streaming is very sparse and the quality too low even compared to regular Blu-Rays. And hopefully the library will never reach the level where everything is available to streaming, sorry, but it would kill the film industry if everybody had access to everything for $9.99 a month. And too few would pay the necessary $50-$70 a month.