These are not just novelty value. They're great for mocking up ideas and I've also used them for generating backgrounds for advertising, for example:

"A black stage lit from above by two spotlights, very dramatic, stylish"

You can also add keywords like "modern/rustic/nature/futuristic" and it will get tuned to your desired style immediately.

Iterate on that for 5 minutes or so and there's my perfect background for a "coming soon" flyer. Way better than I could have made in Canva. Good enough that multiple people have told me the flyers look amazing, and nobody guessed it was AI until I told them.