Earlier quoted context omitted.
There's nothing creative in having someone or something else doing the work for you. "Creating" with an AI is like an executive "inventing" the work actually done by their team of researchers. A team owner "winning" a game played by the their team. That being said, AI output is very useful for brainstorming and exploring a creative space. The problem is when the brainstorming material is used for production.
The first two paragraphs of your argument could be used to discuss whether Photography (Camera is doing most of the work) or Digital Drawing (Photoshop is doing most of the work) are art. Both things which were dismissed as not art at first but are widely accepted as an art medium nowadays.
The work a camera does is capturing the image in front of the photographer. "Art" in the context of photography is the choice of what in the image should be in focus, the angle of the shot, the lighting. The camera just captures that; it doesn't create anything that isn't already there. So, not even remotely the same thing as AI Gen.
The work of Krita/Inkscape/etc (and technically even Photoshop) is to convert the artistic strokes into a digital version of how those strokes would appear if painted on a real medium using a real tool. It doesn't create anything that the artist isn't deliberately creating. So, not even remotely the same thing as AI Gen.
AI Gen, as demonstrated in the linked page and in the tool comparison, is doing all of the work of generating the image. The only work a human does is to select which of the generated images they like the best, which is not a creative act.