Why use RxJS?
Why Use RxJS
First, RxJS and the Observable primitive solve problems that Promises cannot.
A promise is both non-cancelable (in most cases) and can only produce a single value over time. Once a promise has been resolved, that's the end.
Further, Promises are eager, while Observables are lazy.
Third, RxJS provides a large collection of utility operators (functions) for creating and managing the flow of data in an application.
RxJS has zero dependencies and provides TypeScript declarations for use with TypeScript projects.