That's because of people who treat AI like a magical "give me a finished product" button. Someone whipping up PowerPoint slides tends to care more about saving time than maintaining quality - the (usually watermarked) stock photos of yore weren't exactly the zenith of artistic presentation either.
Like any other tool, the quality of output is proportional to the quality of input. You'll get much better results if you provide specifics (detailed description of what you want, reference pictures, iterative clarifications etc.) and have it work on bite-sized pieces of the process (outlining, shading etc.), with manual verification and touch-ups in between. But all that still requires time, taste and experience, which deflates the "AI will replace skilled labor" hype.