As I know, all SE sites inherit current global layout, namely the right-hand sidebar and the left-hand Q/A column.
From my point of view, however, the left-hand sidebar is significantly better in that sense, that it improves my concentration on the main text flow. It happens because the text lines start more close to the center of the monitor, and I scan through the information slightly easier than in the case they start from the left part of the window.
So could it look for example:
It is probably next to impossible that the design would change so globally, still the discussion and critics on this idea is welcome.
Apart from the fact that it is so "by design", what can be telling against implementing the sidebar on the left?
I can think only of the disadvantage, that the ads can be too colorful and make an even more negative effect. But the latter could be tweaked just by adding more space between the sidebar and Q/A section.
Optimal solution would be in my opinion to make Linked and Related side section on the left, because they are useful and not so colorful.
Notifications and hot questions would be better to have on the right side, since they are too contrasting with the background (like the yellow featured note on the screenshot).