Js is a scripting language that relies on the program being scripted to interact with the outside world. In browsers, this is the DOM and xhr APIs. On servers, this is the node stdlib which lets you interact with the system. The fact that this kind of modularity bothers you is bizarre.
It is a modularity that is an unnecessary point of failure compared to other choices available, and involves poor abstractions for Javascript to use things it was not intended to use.
