If your referring to external dependancies as "how many times you require a dependency in your code", then realize that large projects like babel are actually composed of smaller dependencies under the covers: https://github.com/babel/babel/tree/master/packages So wrapping smaller packages in a larger package doesn't change whats happening behind the scenes.

If your referring to "just not having external dependancies at all" then good luck writing anything of value without first recreating the wheel.

As to the question of if the code is modified, thats what semver is for. Production apps should always link to a specific version of a library.