Genuine question: can someone point me to a use case where langchain makes the problem easier to solve than using the openai/anthropic/ollama SDKs directly? I've gotten a lot of advice to use langchain, but the docs haven't really shown me how it simplifies the task, or at least not more than using an SDK directly.

I really want to at least understand when to use this as a tool but so far I've been failing to figure it out. Some of the things that I tried applying it for:

- Doing a kind of function calling (or at least, implementing the schema validation) for non-gpt models

- parsing out code snippets from responses (and ignoring the rest of the output)

- Having the output of a prompt return as a simple enum without hallucinations

- process a piece of information in multiple steps, like a decision tree, to create structured output about some text (is this a directory listing or a document with content? What category is it? Is it NSFW? What is the reason for it being NSFW?)

Any resources are appreciated