Is the Sony FE 24-70mm F2.8 GM Lens sharp? This page visually answers that question. Shown above are 100% crops from a lab-captured 70mm f/3.2 test image. Observe the contrast and resolution of these results.
Is the Sony FE 24-70mm F2.8 GM Lens set to 70mm f/3.2 sharper than the Nikon 24-70mm f/2.8G AF-S Nikkor Lens set to 24mm f/3.2? The image quality comparison above also answers that question. Switch between the results to see the sharpness differences between these lenses.