The problem is that all the popular NPM packages have so much dependencies that you cannot just download a zip file and install the package on your local comput

The problem is that all the popular NPM packages have so much dependencies that you cannot just download a zip file and install the package on your local computer in order for the library to work, you'd need a way to track all the dependencies... PHP (composer) or Java (Maven) are less prone to that issue because a composer package can't have 50 versions of the same dependency, unlike NPM. So even if a composer package has 20 dependencies, it's relatively easy to track down and download all of them. NPM dependency tries are often exponentials, a stupid design decision. Version conflicts should be solved upstream, not by the package manager. But that decision allowed NPM to grow as a business which was eventually bought by Microsoft.