I don’t even understand what the theory is. Plastic is plastic. What does it matter if it’s attached to the bottle?

Yes, that’s true, but JavaScript has very few core APIs aside from basic DOM manipulation. Even things like comparing timezones requires a third party dependency, for example.

I wouldn’t say you need no dependencies in a Java project, but by all means check the average number of dependencies you get with Java or Python and compare it to almost any Node project.

You could probably sample projects on GitHub, look at the dependency graph, and compare.

At least part of it is that JavaScript is not really a batteries included language like Python or Java to even PHP.

You can’t really do anything productive without relying on a third party library.