Here's a practical in this vein but much simpler - if you're trying to answer a question with an LLM, and have it answer in json format within the same prompt, for many models the accuracy is worse than just having it answer in plaintext. The reason is that you're now having to place a bet that the distribution of json strings it's seen before meshes nicely with the distribution of answers to that question.

So one remedy is to have it just answer in plaintext, and then use a second, more specialized model that's specifically trained to turn plaintext into json. Whether this chain of models works better than just having one model all depends on the distribution match penalties accrued along the chain in between.