To me, using ChatGPT or MidJourney to create something is somewhat akin to using a camera to take a photograph. It might be useful here to think back to the very dawn of photography.
When photographs first appeared, there was some confusion about authorship. Is it the person taking the picture who is responsible for the photo? Or is it the camera? Or is it the subject posing for the photo — since a photograph is just a faithful copy of its subject?
In time, photography came to be seen as an art form in its own right. People stopped thinking of the camera as some sort of magical thing.
Meanwhile, people started to understand that the artist was the photographer, as opposed the person posing of the picture or the maker of the camera. Taking a good photograph requires making some intelligent aesthetic choices, and it is the photographer who makes those choices.
Analogously, generative AI is creating a sort of copy of reality — albeit a reality that was scraped from many sources. The art resides in the choices made by the person wielding the “camera” to create something new and unique, only in this case the camera is the software being used, and the subject is the data that was gathered by the software.
From this perspective, it makes no sense to talk about an AI creating an original work. Rather, the original work is created by the human being who provides intelligent and creative prompts to the AI.