As someone who came up in the New Criticism, I’d be inclined to argue that RPGs are more like dances or songs - the work of art is the act played out at the table, not the sheet music or Players Handbook that supports the performance.
My background is not literature so not sure my opinion is worth a lot here (I studied history and philosophy, always liked reading and literature but don't have much exposure to formal schools of thought). When I started out making RPGs, I viewed them, at most, as a craft. I do come from a music background (I play a number of instruments and used to write a lot of music), and for me music is always about the emotional experience. I tend to engage all art that way (whether its movies, books, or music). These days I do think the writing itself can be an art in an RPG, but I feel much of that is also about how it prepares the readers minds for play and how it interacts with them when they access the books during play. When I think back to the RPG books that really inspired me at a deeply emotional level, but also that clicked and made sense so the transition from reading to preparing and running a game was an act of enthusiasm, they achieve this. I also find the act of writing and designing to be filled with the same creative frenzy and passion as other mediums, so increasingly I am inclined to admit to myself a lot of it is in the art realm for me. If I weren't doing this, I'd be making music for example (which I still sometimes do but most of my time is devoted to making games).