I think its relative. If we look at the photos of dioramas, or models, I think you can (to a point) make them look real or possibly substitute them for 1:1 subjects. Alot of things have to line up, the build, the setting, enviroment, and just as important the photograph itself. When you add figures I think they can go a long way to adding a touch of realism to your piece but they still look like figures and they rarely if at all can pass for 1:1 subjects. The detractors to the "charade" are atmospherics, depth of field, placement, scale of foiliage etc. lighting, sculpting, painting and there bottom line, there is no substitute for the real thing.
I do belive that you can take photos of vehicles by themselves and fool the eye. But I have yet to see a figure that can do that in any setting.
Now you can go a long way to make fabric look like fabric. Some dry brushing can do wonders to make a bag look like canvas or other paint techniques can simulate leather, silk, satin, steel what ever. And there are some very clever painters out there.
As I said, its relative. A badly done figure can detract from a well built model and vice versa. But we are all still looking at a model or diorama. Some excellent, some not so excellent and some that wouldn't fool a blind man. Important is that you enjoy your work and like what you do. Regardless of how real or not real it may appear.
Mike
"Imagination is the dye that colors our lives"
Marcus Aurellius
A good friend will come and bail you out of jail...but, a true friend will be sitting next to you saying, "Damn...that was fun!"