Essentially yes, I would give the person using AI to generate an original image the credit as the image’s creator. I’m willing to bet that anything “good” AI generates is a result of many attempts and refinements and a human selecting the best result, and to me that makes it a human-driven creative process using a tool, the same as using a random number generator.

I’m deliberately not saying “copyrightable” because I don’t personally believe that digital files should be copyrightable (since recognising a copyright of a number is insanity), but it should be copyrightable in a society that recognises number copyrights.