Is photography fine art?
Of course there is debate about individual works that transcend the lines; but generally speaking, it is a stand-alone genre of visual art: photography. It can be used as illustration, as record-keeping, as historic documentary or documentation, and also as fine art in the same sense as other printmaking media like etching, silk screen printing or fine art lithography.
Anyone looking for hard-and-fast walls between one form of expression and another are going to be disappointed. Some artists inhabit two or more marketplaces, just like crossover singers. History and "luck" also play a part in which artists are recognized in which categories.