> But what is it good for? ("What's in it for me?")
> What are the use cases?
I think the examples on the home page and in the "getting started" answer these questions to be honest. Do you feel it's unclear or something is missing?
> How is it difference / how does it improve on / when should I use it instead of / ... lodash, ramda, functional.js, RxJs, etc.?
I think some of that info is implicitly there in the docs, but I think this is good feedback. I should probably have a page comparing lfi vs other libraries.
To answer here though, for most of the libraries you mentioned, they don't provide support for _concurrent_ async iteration (and some of them don't support even sequential async iteration).
RxJS is the exception there I think. Although, I think lfi has a bit of a simpler API (that also matches the sync versions of the APIs) that's primarily designed for iteration rather than generalized observables. Plus, I don't _think_ RxJS has the same performance characteristics around tree-shakeability.