It started as CommonJs ([1]) with Server-side JavaScript (SSJS) runtimes like Helma, v8cgi, etc. before node.js even existed but then was soon totally dominated by node.js. The history of Server-side JavaScript btw is even longer than Java on the server side, starting with Netscape's LifeScript in 1996 I believe. Apart from the module-loading spec, the CommonJs initiative also specified concrete modules such as the interfaces for node.js/express.js HTTP "middlewares" you can plug as routes and for things like auth handlers (JSGI itself was inspired by Ruby's easy REST DSL).
The reason for is-array, left-pad, etc. is that people wanted to write idiomatic code rather than use idiosyncratic JS typechecking code everywhere and use other's people packages as good citizens in a quid pro quo way.
[1]: https://wiki.commonjs.org/wiki/CommonJS
Edit: the people crying for an "authority" to just impose a stdlib fail to understand that the JS ecosystem is a heterogeneous environment around a standardized language with multiple implementations; this concept seems lost on TypeScripters who need big daddy MS or other monopolist to sort it all out for them
What is this crap statement?
So you want type-checking because it helps you catch a class of errors in an automated way, and suddenly you have a daddy complex and like monopolies?
Claiming this says a lot more about you than people who use TypeScript.