Nvidia 1080TI and all settings at high...depends on how the graphics are rendered.
even if the resolution is 4K, if the texture quality at lower settings results in low quality or "blurry" imagery, then even if it's a 4K resolution, it'll still look like crap.
What are your graphic settings?
Take some screenshots by pressing the Win+PrtScn keys on your keyboard, then upload those pics to https://postimages.org and then share those pics here.
Also, what graphics card are you using?
AMD or Nvidia?