Python has no standard packaging. They even deprecated and removed distutils (another terrible idea that caused a lot of busywork). The only way that python supports packages is via 3rd party external solutions.
Yeah, the distutils clusterfuck is another excellent reason someone might "insist on not using the standard packaging solution for the language": it's specifically and only the packages that did use the standard packaging solution for the language, distutils, that got broken when distutils was removed from the standard library.
I mean, I understand the desire to remove distutils. It sucked. It was the least Pythonic package in the whole Python standard library. But removing it was even worse, because it means you can't use old versions of most Python libraries with recent versions of Python.
Python has no standard packaging. They even deprecated and removed distutils (another terrible idea that caused a lot of busywork). The only way that python supports packages is via 3rd party external solutions.