I argue there is a difference because of the nature of the work. Machines aiding in farming is only a good thing, because it can maximize output and minimize input. People (largely) don't care about the process of how it was grown, but rather having the product to eat (Of course there's cruelty free agriculture, organic, etc. but stay with me here). But artistry is a personal thing, and maximizing the output of art pieces isn't something that most are interested in. Art is a uniquely unquantifiable subject, and we want it to have a personal and emotional connection to both the creator and the viewer, something that is lost when AI boil it down to it's essential components and rebuild them in it's image.
I think that this doesn't really help artists as much as just do it for them. Art, the way I see it, requires a human to do because it is something that requires emotion, something a robot could replicate but not feel. For example, a gut wrenching image of innocents being beat by police is gut wrenching because it's something that exists in the real world, and the artist and the subjects are real and their emotion is real. But a computer generated image only has a likeness; it doesn't have actual emotion.
I aldo don't think that it makes it "cheaper, more accessible, and allows more people to create". Digital art supplies being something readily available and relatively cheap to their classic counterparts is what makes things more accessible, and to make it more so would be to drive the cost down or something. Having the computer draw for you isn't exactly creating art.
And art isn't a commodity and I argue it shouldn't be a commodity. It's something, again, personal and special.
And this doesn't end at the visual arts, I think it applies too to writing. AI could write what's written in my journal word for word but my journal would have more value just by virtue of it being written by me.