Often, you need IPC merely to communicate with a child worker process. I've seen quite a number of projects that needlessly roll their own solution when one can just use the built-in process.send() method.
Of course, this doesn't cover all the use cases of this particular library, I just think it's worth pointing out.
It seems a lot of people (including me) have made projects like this, but it would probably be most efficient if one project emerged as the standard (it's surprising one hasn't).
While writing my library it had me wondering if maybe I could design my application differently so that I didn't have to use any IPC, but I couldn't think of a way.
So yes, very surprising.
I'm the developer of this library by the way, and I'm really looking for issue submissions and feedback. Any is much appreciated.
Of course, this doesn't cover all the use cases of this particular library, I just think it's worth pointing out.