In New York City, everyone has an opinion. Ask someone where to get the best slice of pizza and you may have inadvertently started a street debate on it. This is an important subject for New Yorkers.
What is art falls into the same category. Good luck getting much in the way of a universal definition or agreement on this subject. The history of art is filled with comments and scholarly writing on it.
For some, it is their career. They get paid for their opinions on art. They probably have advanced degrees in art history and write columns in the media as well as books.
So they are “art experts” They base their opinions on many different things including their personal tastes, even when they don’t acknowledge that point.
But mostly, when art critics write about art they are writing about the state of art, different schools of art, particular artists, etc. Their writing has an understood aspect to it. They don’t often feel the need to explain why something can be considered art.
Maybe it’s really a good thing that there isn’t one gospel definition of what art is. Yes, art is very much subjective. It IS in the eye of the beholder! Your feeling about it is all that really matters when observing a piece.
The fact that there is no single definition means that we also have a wide variety of artistic styles. It is not necessary for a work of art to have only one definition.
We should celebrate that art doesn’t fit neatly into one category. And yes, photography is also art so long as you view that way. I do! Just because someone calls it art doesn’t mean that you have to like it. Do you know of a universal definition of art?