This lens seems to be completely predictable.
Sony has clearly a methodology which it is following with E-mount design, only slightly modified for FF.
In every lens design compromises need to be made. The main swings are between sharpness, distortion, size and contrast (although this is a partnership with coatings).
Sony have given sharpness and size the priority which is perfectly understandable. They figure that software can correct distortion but not the other issues.
Generally all E mount lenses, especially zooms, have above expected distortions.
The issue with software fixes is that they reduce corner resolution. Additionally many soft corner issues are actually field curvature so are more pronounced close up.
On balance Sony have done the right thing by this lens IMHO for those that want a sharp lightweight walk around. Sony assume that serious landscape or portrait folk will probably use primes.
I expect Sony at some point to produce a high quality f2.8 zoom. But don't expect much price or weight difference from the Canon 24-70mm f2.8 II (the current benchmark for mid range zooms)