Both lenses are rather limited in utility. Typically with 24-70mm zooms, they are designed with a f/2.8 aperture, and are intended as a trade-off where you give up some zoom range to gain subject separation (you often give up IS too). In regard to the Canon 24-70mm f/4, although subject isolation capability is not the same as an f/2.8 zoom, you do get IS, as well as pretty serious macro capabilities (0.7x).
Looking at the tests at Imaging Resource (I'm not a Sony user, and I don't own that particular lens for Canon, so I'm referring to a neutral third party), neither is super sharp wide open, with a slight edge to the Canon for corner-to-corner sharpness at all focal lengths, and a slight edge to the Sony for center sharpness at all focal lengths. In terms of distortion and vignetting, the edge definitely goes to the Canon for being more optically corrected; however, it's pretty typical for Sony zooms to have fisheye-like distortion at the wide end and bad pincushion distortion at the long end, with so much vignetting that the corners are >5 stops darker than the center at the wide end. Then again, the Sony is intended to be corrected via software in camera, so you'd never even notice that kind of distortion or vignetting in your images. https://www.imaging-resource.com/lenses/canon/ef-24-70mm-f4l-is-usm/review/https://www.imaging-resource.com/lenses/sony/fe-24-70mm-f4-za-oss-zeiss-vario-tessar-t-sel2470z/review/>>3313409>Lenses for the Sony are insanely sharp
This is a pretty stupid generalization. It just goes to show that even the most ardent Sony fanboys have not done their research. Any lens is a set of compromises, even a Sony G Master or a Canon L lens.