It is my view, that the whole "art is relative to the viewer" thing is a kind of philosophical laziness that's been inflicted upon us. Certainly, we all have things we like more- or less, but that's not the question. Art is by the artist and for the artist, not the arts consumer. The "beholder" is not relevant to whether or not art is being made, the artist and their intent are. Whether the beholder gets it or not is not part of the "is it art" equation.
We also have been taught to shy away from questions like "What is beauty?". This is another outcome of the sloppy thinking that came out of the Deconstruction and Postmodern philosophical drivel of the 20th Century. In "The Great Transformation" by Stanciu, he launches an absolutely robust definition of beauty (indeed, his argument is beautiful itself) that should be tattooed inside the brain of all artists (Ch. 22).
The nature of art, beauty, and meaning is a difficult conversation, but that doesn't mean we should throw our arms up and say "well, it's just whatever you want it to be". It's one one of the many ways that "crap" gets promoted as great stuff since there isn't even an attempt for objective standards.
(And a pox on Jacques Derrida for taking us down this rathole in the first place.)