At various points in my career, I've seriously considered writing an effects library very similar to this one because the benefits in a sufficiently complex system are clear to me. But ultimately, JavaScript doesn't have the functional primitives to make a library like this very ergonomic. In particular, the lack of syntactic sugar for function composition (e.g. a "pipe" operator such as |> as seen in functional languages) means every operation needs to be composed via method calls and argument passing, which adds a ton of visual noise that detracts heavily from the conceptual simplicity of the library.

If your project, as a whole, benefits heavily from a functional style of programming, you are likely better off using one of the many functional programming languages that compile to JavaScript, like ReScript, OCaml, F#, or Scala.