The thing with beautiful prose is it doesn't exist in isolation, at least not in my limited experience. Authors who have great prose are usually good at the other bits of writing too. Maybe not great, maybe not as good as the Dan Browns of this world, but by its nature good prose is well structured, and I think that ties into understanding structure in a broader sense, too. I dont think you can write beautiful prose and produce only a word salad novel. Maybe I'm wrong. Maybe those just never get published.

Side point; I enjoy Lovecraft a lot but I find his prose waffly, vague, and overwrought in places. I read him for his ideas mostly. I appreciate this is subjective.