Why is js code poorly documented?

Question

Documentation

Good afternoon, I work with node (express, etc.).

All projects that I met (REST API) are documented in a separate swagger.json file (the js / ts code itself does not contain documentation), why is jsDoc almost not used for automatic generation?

I also opened the sources of various libraries, all in TypeScript, but I did not see any specific code documentation.
I came to the world of JS from PHP, and almost every step, every variable, method, class is documented there.

Answer 1

Only complex sections of code, complex processing/calculation logic, special methods in classes, and implicit (by code) event subscriptions are documented.
Open the code of the game "engine" in js or encrypt / hash libraries in js, and you will immediately see code commenting in difficult (to understand) places.