You've missed screen size as a factor. TVs are getting larger by about an inch per year since flat screens took over, and that trend doesn't seem like it's stopping any time soon.
There's also the type of content and your personal visual acuity. If you're young, your eyesight is probably quite capable of resolving much finer details than normal 6/6 vision. I can tell the difference between 4K and 8K at a normal sitting distance on a 65" TV.
However... the difference isn't enough for me to care. I'm much more interested in brightness, colour, framerate and a load of other things over another resolution bump.
There's also the type of content and your personal visual acuity. If you're young, your eyesight is probably quite capable of resolving much finer details than normal 6/6 vision. I can tell the difference between 4K and 8K at a normal sitting distance on a 65" TV.
However... the difference isn't enough for me to care. I'm much more interested in brightness, colour, framerate and a load of other things over another resolution bump.