What is art? who knows, and basically it is irrelevant. there are collectors who choose art for the investment, art to conform with and some - art because it gives them something nothing else can. I bunch all arts together, including music, dance, performance and visual ( and of course all subdivisions of)
The definition of what art is inevitably turns art into an object that can be sold and/or marketed.
...that's one side
However, what causes art to be made, conceived and strife for?
I've got years of art history and philosophy, but it in the end, my experience is the one I can relate to.
A compulsion to express oneself, express that what oneself isn't aware of, but knows and needs to bring out to the open.