I think the reason is JS doesn't have much of a standard library. Java, C#, Ruby, Python, Rust, Go, and many others come with a large library you can use to write non-trivial applications without ever needing to fetch an external dependency. JS, particularly outside of Node, doesn't have that. To get functionality most other languages/runtimes include out of the box, you need to write a bunch of code yourself or pull in a dependency to use someone else's implementation.