I don;t usually get into these discussions, for one thing I do more content creation that anything else, and most of my renders either fall into the WIP testing or Promo type stuff so I don;t think in terms of ART all that often. However I would like to interject one thought here. In what way is Posing, Lighting and Rendering  a model in Poser all that different than Posing, Lighting and Photographing a model? Yet Photography is concidered Art even to the point of having whole coursed build around it.

The bottom line IMO is that ART is in the act of creation and yes you are creating something wheither you use all premade components or not, after all a cook doesn;t make all of the ingredients in a meal, nor a baker all of the ingredients of a cake, but those ingredients do not automatically fall together to create something that tastes good.

Enjoy what you do, and if others (even a few) enjoy the results, feel happy!