Soft? I find it about equal to the RF 24-70 2.8 in real life.
If you pixel peep at the-digital-picture, it shows as sharper then the RF 24-70 2.8.
There are other imperfections with chromatic aberrations etc, but I think it is plenty sharp and a gem of a walk around lens with its size.
If anything the RF 24-70 2.8 needs some help if you compare it to Sony's GMII.
I have the GMII and find it to be pretty much as sharp as primes.
View the image quality delivered by the Canon RF 24-70mm F2.8 L IS USM Lens using ISO 12233 Resolution Chart lab test results. Compare the image quality of this lens with other lenses.
www.the-digital-picture.com