Most consumers are never going to have colossal screens. I finally jumped in and picked up a 65" 4k qled tv at an after xmas sale. The reality is the biggest jump is the HDR. Switching back and forth between 1080 and 4k I'm hard pressed to tell a significant difference. OTH, turning off HDR makes a very noticeable difference in picture quality in both 1080 or 4k mode.
Also, don't know how old you are, but there was a time when everyone was worried about the same thing with personal computers. Eventually the performance exceeded what the overwhelming majority of people need and people started owning their computers for a lot longer time. I really haven't seen a need upgrade my pc in a long long time. Though, I could probably use a little bump in performance for photoshop and my new dslr
Even so, it could just be the software isn't taking advantage of all the cores (yet). Ergo, an upgraded pc may only make a small difference.
I'm curious what new tricks 8k or 16k will have beyond resolution gain?