I don't think that's a fair comparison, the only two libraries that are related to the actual packaging system in that list is yarn and NPM. The rest of them have to do with the complexities of actually having your code runnable in the maximum number of browsers without issue. If python was the browser scripting language, it'd likely have the same issue.

Is there a python package that transpiles and polyfills python3 to work in python 2? 2.7? 2.5?

Also, unrelated to your comment, a lot of people are dunking on npm for the black hole that is node modules (which is valid), but also saying it's not pip's fault a lot of packages don't work. It's not npm's fault the package maintainers are including all these dependencies, and there are some 0-dependency packages out there.