One of the ways that I have better understood the usefulness of a Reactive Streams-based approach is how it simplifies a non-blocking IO call.
This post will be a quick walkthrough of the kind of code involved in making a synchronous remote call. Then, we will demonstrate how layering in non-blocking IO, though highly efficient in the use of resources (especially threads), introduces complications referred to as a callback hell and how a Reactive Streams-based approach simplifies the programming model.