Why are building textures blurry in Lost Ark at 4K with DLSS?

I can't stand it—at 4K, the building textures in Lost Ark are blurry. This kind of smearing on a 5090 is simply unbelievable for a flagship card. I first tried switching DLSS to 'Balanced' mode; while I gained 20 FPS, the blurriness got even worse, which made me furious. I used the GamePP DLSS/FSR Image Sampling Calibrator to raise sharpening from 50 to 78 and locked the render scale to 100%. RivaTuner confirmed an increase in effective pixels, with GPU temps at 62-68℃ per AIDA64 and clocks at 2600 MHz per GPU-Z.