Yeah, though I there is the same issue the other way round: Great prompt understanding doesn't matter much when the result has an awfully ugly AI fake look to it.

That's definitely true, and the medium also really makes a big difference as well (photorealism, digital painting, watercolor, etc.).

Though in some cases, it is a bit easier to fix visual artifacts (using second-pass refiners, Img2Img, ultimate upscale, stylistic LoRAs, etc.) than a fundamental coherency problem.

I was disappointed when Imagen 4 (and therefore also Nano Banana Pro, which clearly uses Imagen 4 internally to some degree) had a significantly stronger tendency to drift from photorealism to AI fake aesthetics than Imagen 3. This suggests there is a tradeoff between prompt following and avoiding slop style. Perhaps this is also part of the reason why Midjourney isn't good at prompt following.