Took your invitation to look at the larger pixel peeping image and for some reason that file looks pretty sharp. The bridge is in focus and there is little evidence of blur. Check it out and see if you see the same.
If someone else confirms this it would put the culprit in the post processing department.. maybe some kind of image depth or resolution downsizing. Or maybe noise reduction is loosing the detail.
AE-1, T90,EOS Elan 7e, EOS-M, 7D, 5D3, 1dx, ef40 2.8, ef 85 1.2ii, ef100 is 2.8 macro, ef300 2.8ii, ef400 2.8ii, ef600 is ii usm, ef8-15 f4, ef16-35 ii, ef24-70 ii, ef 24-105, ef 70-200, 2xext ii, 2xext iii, 1.4x ext iii.