Idiomatic JavaScript doesn’t use currying. If you add it to your code base, you are now siloing your project to folks that understand currying which has two problems: 1) hiring Joe Schmo to add/maintain will be harder 2) folks that understand currying will almost certainly be more happy & productive in a language that has currying by default & is idiomatic.

For instance, the audience that sees fp-ts as a necessary, useful library to code in a manner they find most appropriate will find JavaScript/TypeScript ergonomics verbose, hard to read, and require someone with functional programming experience (see the verbosity according to their docs of TypeScript+fp-ts vs. PureScript: https://gcanti.github.io/fp-ts/guides/purescript.html). That audience would be better suited doing compiled option such as the aforementioned PureScript, or js_of_ocaml, ReScript, derw, Idris, GHC.js/whatever the new GHC compiler JS output is, or similar option. These languages will have the idioms of fp-ts without the heavy reliance on singularly library most of the TypeScript community doesn’t understand that bloats their code bases without requiring the safety (someone can just call .value on a Maybe/Option breaking the safety). (This is not a knock against fp-ts which is a marvel in & of itself, but the audience doesn’t line up with the idioms of the average TypeScript project).