Is the Sony FE 24-70mm F4 ZA OSS Lens sharp? This page visually answers that question. Shown above are 100% crops from a lab-captured 70mm f/5.6 test image. Observe the contrast and resolution of these results.
Is the Sony FE 24-70mm F4 ZA OSS Lens set to 70mm f/5.6 sharper than the Sony FE 28-70mm F3.5-5.6 OSS Lens set to 50mm f/5.0? The image quality comparison above also answers that question. Switch between the results to see the sharpness differences between these lenses.