Earlier quoted context omitted.
It's terrible at the niches I actually have expertise in, which are in mathematics. I'd guess an expert is going to find the flaws in anything it's doing in their field. That being said, if you're just trying to e.g. see what some GUI library can do then it's pretty useful to get something going. I personally would prefer not using it in anything that's not very much a throwaway test project though, but that is my lu…
But doesn't your argument actually mean it is terrible at absolutely everything in a very subtle, convincing way, so that it takes an actual expert in the field to tell that the generated text is not a profound revelation but a bag of nonsense? Meaning, is the answer in the field I'm not an expert of good, or am I simply being fooled by emoji and nice grammar?
Or you can do like some of the others suggest and eliminate pure vibecoding. Just use it as a back and forth where you understand along the way and make well-reasoned changes. That looks a lot more like real engineering, so it's not surprising the other commenters report better results.