I recently had a similar discussion with people using npm for building a CSS framework library. I tried to explain the concept of getting a pre-downloaded tarball and using "make" (or similar) to produce target artifacts from source files in a deterministic, repeatable and reliable manner, without relying on any third-party servers being available and without pulling in dependencies that might have changed.
It seems the concept was entirely alien to programmers younger than me.
It seems the concept was entirely alien to programmers younger than me.