That is precisely it. Generative AI is a tool, just like a digital canvas over a physical canvas, just like a canvas over a cave wall. As it has always been, the ones best prepared to adapt to this new tool are the artists. Instead of fighting the tool, we need to learn how to best use it. No AI, short of a true General Intelligence, will ever be able to make the decisions inherent to illustration, but it can get you close enough to the final vision so as to skip the labor intensive part.
He’s right, though - unless there are real legal repercussions or it’s an impossible task, just say “yes”. Worst case scenario, you’ll do a bad job of it and whoever requested your service won’t do it anymore.