Why are underwater textures blurry on my Zotac RTX 5070 Ti 16GB?

I wondered if the 50-series DLSS algorithm over-erases textures; while exploring the underwater city, metal rust looked like it had a soft-focus filter. I tried switching DLSS from Quality to Balanced mode, which gained 8 FPS but made the blurriness worse, leaving me very disappointed. I used the GamePP DLSS/FSR Image Sampling Calibrator to raise sharpening from 50 to 72. Confirmed via RivaTuner that textures sharpened; GPU temp stayed 62-68℃ per AIDA64 and clock hit 2580MHz per GPU-Z, while fans ran at 1600 RPM per HWInfo.