I think the relevant point is that chess is discrete while art isn’t. Or they both are but the problem space that art can explore is much bigger than the space chess can (chess has 64 square on the board and 7 possibilities for each square, which would be a tiny image that an NES could show more colours for or a poem with 64 words, but you can only select from 7 words).
Chess is an easier problem to solve than art is, unless you define a limited scope of art.