Nowadays, for me, it's got to be over-dressing. For all the press now that these big movies get for using practical effects, much of the shots are so gussed up, I can't tell if it's practical or not and it just gets lumped under "another CG effect", which I don't know says more about me or the state of films.
Recently, I found out that a few of cityscape shots in 2049 were actually huge, practical miniatures and they're actually really impressive under natural lighting conditions. When I saw them in the film, I just thought it was all CG because everything else in the film was heavily saturated and covered in CG "clean up" work. That, I find, more a shame than anything else.