Why does Ratchet & Clank look blurry in 4K mode?

Ratchet's face looked like it had a soft filter applied when using DLSS Quality mode in 4K. I tried switching to DLSS Balanced, which gained 8 FPS but made the blurriness worse, and high sharpening caused chromatic aberration. I used GamePP DLSS/FSR Image Sampling Calibrator to set sharpening intensity to 75 and render resolution to 100%. RivaTuner showed significant improvement in effective render pixels. GPU-Z confirmed the GPU clock held steady at 2610MHz, and the visual fidelity is now sharp and clear.