I wonder why the 24-70 f/2.8 has no VR

Even if that decrease could be demonstrated on a print, I would trade that bit of compromise for the increased % of shots that are in focus. Bumping up iso increases noise, so pick your poison. Tripods can be a pain and prohibited in many museums. Try taking a shot of the Declaration of Independence inside the National Archives. No flash, no pods. You're looking at iso 4000-6400, F2.8, 1/30s or less in there. I prefer to own a few zooms rather than a dozen primes, so don't have those 1.8 lenses.

In my less than perfect hands, VR allows a greater % of sharp shots.