What performance should I expect on 4K TV?

Quick question. I just did a quick test with my living room 65 inch 4k tv and noticed that the picture quality was not that great. For example, the picture quality on the cockpit displays were very jagged and not too clear. I would have thought 4k would make things very crisp and sharp. Did I miss something? I did change the resolution and rendering in the game settings to match resolution of my tv.

So what did I miss?