I take it you haven't seen the 4k versions streaming on Disney+? They're sourced from the same problematic 1080p masters used on the old Blu-rays, just upscaled to 4k and given an HDR grade that's net effect is only to make the image much dimmer. (They aren't really HDR, because no highlights extend beyond the SDR range.) They still look over-processesd with grain removal and edge enhancement artifacts. The UHD Blu-rays are guaranteed to be the same transfers Disney+ uses.