Hi,
the "batteries included" argument was a huge selling points years ago (when Aaron Watters wrote "Internet Programming With Python", for instance) but I think the situation has changed quite a bit since then.
My own experience is that for most of the packages in the standard library, there exists "better" (for some sense of "better") packages on PyPI. The reasons why this is so are obvious or have already been discussed (e.g. in
https://www.python.org/dev/peps/pep-0413/ ).
It has also been discussed that some people can't rely on anything outside the standard packages, due to the constraints of their company or their field.
I can see some benefits in the idea, if I understand it correctly, of a two-tiers standard library ("core" and "standard").
S.