That's not quite true. If you can put up with 40-60 FPS and dips into single figures in some games and can handle the fact that some games will need the settings reduced heavily in order to meet that target then it's fine.
Reviews of both the 980ti and Fury X are both a little economical of the truth. Reviews always are. They cherry pick a scene, then run it for a minute or so. Not indicative of actual real world performance at all as I found out.
I had a 4k and 980ti and it ran everything I wanted to play fine. I didnt have to heavily reduce any game settings or get single figure FPS. It all depends on what your gaming experience expectations are. One persons playability is another persons chug chug.
When people say "4k is not there yet" its a terrible sweeping statement backed up by one persons opinion.