If you mean reading is an art in the colloquial sense to mean an acquired skill, as how someone might say “drinking is an art” or “driving a car is an art” then sure.

If you mean reading is an art form in the same sense as writing, painting, or sculpting are forms of art, then no.

I got quite far into the comment thread and was surprised to see nobody mention the concept of New Adult novels.

It’s a somewhat newer marketing category, from Wikipedia:

St. Martin’s Press first coined the term in 2009, when they held a special call for “fiction similar to young adult fiction (YA) that can be published and marketed as adult—a sort of an ‘older YA’ or ‘new adult’”