I’m waiting for holographic projectors and motion gesture commands

It's situational. Some people have tiny spaces and are in the range of 3.5 to 5 feet for the average tv screen size of 50" to 65". In my bedroom when I am lying back watching tv I am 6 to 7 feet away from my 55" tv which is too far to notice the benefit of 4K but when I am gaming I am usually sitting at the end of the bed closer to the tv which is 3.5 feet from my tv and is noticable to me thus I benefit at times having 4K resolution.

Now I wouldn't suggest 55" screen for PC gaming or movie watching but my son at his computer sits roughly 2 feet from the PC monitor when watching Movies and even closer when Gaming... My guess is when working in that environment using a 30" monitor probably benefits hugely from higher pixel count....

Of course if a person were to by a projector or large monitor 75" or more then a person could sit farther away from the screen since the pixels are getting larger and still make out the fine details with a 4k.....

Since the average tv size is 50" to 65" I say 4k is still viable in some situations...... A situation where it probably doesn't work my parents have a huge living room and their sitting positions will not ever get them close to the screen and would benefit greatly from a large screen 75" or more but sadly did not buy a very large tv like they were planning and went with a 55" TV. My parents, as well as guest, will never sit close enough to the 4K TV setup to benefit from pixel the increase.

There could be an exception to the rule for others .... there does seem to be a push to Ultra-wide viewing ( Cinemascope Films) where extra pixel count would be benefit. I love Ultra-widescreen because it reduces the need to pan and zoom as much since much more information can be displayed without zooming or panning. It also gives long areas with lots of information (such as a bar scene or team sports scene) where there is lots of people or other actions giving much more life the scene. Also, If the film zooms in, it makes objects closer (for instance a closeup shot of a face) the face may take up a 1/3 of the screen and able to take advantage of all those pixels. When the film zooms out the face or object gets smaller and less pixels are used to show the same face the loss of detail can be noticeable. 4k pixels can definitely help these types of scenarios but is highly reliant of whoever is filming the video to know what works best......

Again situation, but 4k has its place and still is needed. I'm still hoping Ultra-widescreen will take off but its still a niche market despite the benefits. HDR has not been out that long and has more momentum behind it and is easier implement when factoring technology standpoint. However 8K is not really needed on the comumer side yet you hear rumors of Companies already working to make it happen. There is a point where we as consumers will probably just stop because it doesn't apply to enough consumers to matter.