The reality, however, is that if you took this point of view, you will spend your time reinventing the wheel, introducing bugs and wasting resources. That's how it works in real life.

If someone already wrote the base code, we can always fork it and fix a bug or add a feature ourselves if it runs contrary to what the original authors desires.

Fair point. One does run the risk of having bugs in code out of their control by using a package manager such as NPM, but one gains a swath of other programmers inspecting the modules for bugs. And in module repositories for interpreted languages, its very much in your control to fix any bugs you might find, regardless of what the maintainer might say about it.