I have successfully used AI to generate generates "concept art" and logos for projects, presentations, and publications. It seems to make the outcomes more approachable, more understandable, and certainly more aesthetically pleasing.
It is not a matter of replacing human effort or skill, and certainly not a matter of adding cheap ornamentation. If AI weren't available, I usually wouldn't have the time, money, energy, or will to pursue those illustrations. I say this as someone who has historically spent what seems like a vast amount of time, energy, and money sourcing art. In a former life as as publisher I even hired full-time artists and insisted on custom artwork. But my current work no longer has that luxury. I still want the best possible looks, and the best possible outcomes.