So "GitHub is every single programming language's centralized package repository, because lots of code is hosted there" ?

> Python supports installing from other non PyPI indexes > 95% of Python packages are installed from PyPI, but just like Go can also install from non-Github sources, Python supports installing from other non PyPI indexes[0] or even from a Git repository directly[1] like Go.

And yet there is a clear difference between source distributions and pip/npm/rubygem/cargo packages - and between tooling/ecosystems that ONLY support the former and those that MAY use either and unfortunately mostly use the latter.

> What is it that you imagine Python or NPM packages consist of?

Something like a script that runs as part of the package that downloads a tarball, modifies package.json, injects a local bundle.js and runs npm publish (see this post). Usually also hosted at the default, centralized, authoritative source run by the maintainers of the package management tool.

But I'm repeating myself.

> (or do they? do they just use https to check out?)

Maybe try it out or read the docs first.

I'm closing with this:

> NPM, Python, Rust, Go, Ruby all suffer from this problem, because they have centralized and open package repositories.

is either wrong or disingenuously misleading, requiring nothing to apply to every single thing, depending on how you slice your definitions. It does not hold any water, that is my entire argument.