> You want to benefit off the work of others, and bear zero cost. What if you just built those libraries yourself
No one can do that to any large scale. That is all there is to say about that.
And all my projects are open source. I give back to the community and to science (see below).
> To make you more productive?
There's intent, and then there's reality.
I work in scientific programming, and scientists are absolutely struggling with software development. Not programming, but everything related to package management, version control, distribution, different languages, incompatible ecosystems, etc.
There is complexity in the boundaries of packages, languages, and ecosystems. That is unsolved and no one seems to care about it as long as you can do this cool things with your own language.
Someone's intent could be to make python package management easier. The reality is that having only a few people adopt that can make the entire community suffer.