the 4K market doesnt exist yet.
Sadly now on the disk side it never will. Sony really screwed any chance when they left it off the PS4 Pro. The XBOX does have it but for it to any chance Sony needed to help. Good enough will win the day. For those who say big deal who wants disks anyways if you every saw the difference on a TV or projector capable of seeing it you would know. Plus to stream 4k you need consistanlty big pipe and you better have a high data cap and it will look almost as good as 1080 on Blu Ray but with mediocre at best audio.
Sony sees the PS4 (and its next generation PS5) as a totally streaming high definition box. The trends indicate most young men arent streaming prime time network produced entertainment, they largely spend theyre high def display time playing and watching others in online global video games. The rise of pro online gaming tournaments, twitch.tv and even ESPN now showing these gaming competitions tells you a lot.