Rust likes to do things neat and proper and inclusive and community and zero-cost (or ALARA [as low as reasonably achievable]), and so on.

But there's no theory of standard library that they could implement. Shipping things together makes sense, but the maintenance burden is already significant, and there's also no theory of "ethically cloning open source maintainers".

I'm also quite squeamish when I think about all the unvetted dependencies, so yes, there's definitely a need, but I don't think slapping a stdlib tag on millions of lines of code would lead to great things.

But sure, I think someone could champion the case to introduce a process for adding projects to the standard packages. The projects would need to show some competence, commitment to quality and security. And the process obviously needs to have an orderly procedure for deprecation, and for "non maintainer updates" (like Debian has, for example).