Of course changes but afaik it's backwards compatible.

I don't think the OP was making a point about backwards compatibility, but how the language itself has remained stable (sign of good design?). That is not the case for the majority of languages, except for maybe Ruby. Javascript in particular looks nothing like code from 6 years ago.

Furthermore, you rarely just plain JS. It's always another behemoth framework such as React or Angular.

I challenge anyone to upgrade a project from Angular ver 5 to the latest. It's possible but you'll also question whether its possible for you to quit software engineering and learn woodworking.