In Biology, most of the paper seems to be spent explaining why the new result is relevant and how it differs from previous work. It's usually dry as a bone but I wouldn't call it obfuscated. Readers should probably have Wikipedia handy for defining terms.

Long papers tend to have a heck of a lot of research. A short paper could be about a single experiment, but often a writer will publish a larger body of work in one paper. Value added, I suppose.