https://262.ecma-international.org/16.0/index.html
I don't agree. (And frankly don't like using JS without at least TypeScript.)
It has some strange or weirdly specified features (ASI? HTML-like Comments?) and unusual features (prototype-based inheritance? a dynamically-bounded this?), but IMO it's a small language.
- Regular expressions - not just in the "standard library" but in the syntax.
- An entire module system with granular imports and exports
- Three different ways to declare variables, two of which create temporal dead zones
- Classes with inheritance, including private properties
- Dynamic properties (getters and setters)
- Exception handling
- Two different types of closures/first class functions, with different binding rules
- Async/await
- Variable length "bigint" integers
- Template strings
- Tagged template literals
- Sparse arrays
- for in/for of/iterators
- for await/async iterators
- The with statement
- Runtime reflection
- Labeled statements
- A lot of operators, including bitwise operators and two sets of equality operators with different semantics
- Runtime code evaluation with eval/Function constructor
And honestly it's only scratching the surface, especially of modern ECMAScript.
A language spec is necessarily long. The JS language spec, though, is so catastrophically long that it is a bit hard to load on a low end machine or a mobile web browser. It's on another planet.
By the time you understand all of typescript, your templating environment of choice, and especially the increasingly arcane build complexity of the npm world, you've put in hours comparable to what you'd have spent learning C# or Java for sure (probably more). Still easier than C++ or Rust though.
Modules were added in, like, 2016.