AI image generation is a tool.
Like other tools, if you don't know how to use it, you can't get great results.

Generating good maps with Ai is almost impossible at the moment. The details and consistency required are out of reach.
Also, since most maps are quite large. Ai can't handle very large image. Upscaling can do miracles but is not that useful on maps.
But it's great to generate map elements such as icon or brushes.

So far, Dall E 3, which what just released, has the best image composition and it the closest thing to an Ai map generator.