I understand what you mean, and also understand the nihilistic stance, however, the same way humans don't exist in a separate plane, the selfception and empathy toward others (which is not unique to us) allows a more than zero sum interpretation of art. Naturally the technical part can be reproduced by machines but the metaphysical part cannot. What becomes interesting is the notion that the metaphysical can be created post-hoc, which puts us squarely in the same situation as other poster wrote by quoting the passage of "The man in the high castle".

It's maybe stupid for you, but clearly not for everyone. For example, an AI could create the History of a planet that we do not know it even exists; meanwhile, I won't call stupid those people interested in reading that, but currently I'll read the History of this planet written by humans, if asked. In a nutshell, my point is there is value either way, but poems written by machines? I will leave those to scientists and scholars, at least for now.