Is the Canon RF 70-200mm F4 L IS USM Lens sharp? This page visually answers that question. Shown above are 100% crops from a lab-captured 135mm f/8.0 test image. Observe the contrast and resolution of these results.
Is the Canon RF 70-200mm F4 L IS USM Lens set to 135mm f/8.0 sharper than the Sony FE 70-200mm F4 Macro G OSS II Lens set to 70mm f/4.0? The image quality comparison above also answers that question. Switch between the results to see the sharpness differences between these lenses.