usually packages use packages in any worthwhile language with useful packages and desire for code reuse...

It's also funny to hear this about Python which, arguably, has biggest std and amount batteries included out of the box.

Python's stdlib is not really something to brag about. Very inconsistent, multiple ways of doing the same thing, a lot stuff in there people recommend against actually using...so much cruft acquired over decades.

It's why projects use so many packages in the first place.

Indeed. The standard library was primarily designed in, and for, an era where you couldn't just download multiple megabytes of third-party code on a whim.