An RFC was recently merged to unblock this: https://github.com/rust-lang/rfcs/pull/3963
The implementation on this has started.
Something to keep in mind is https://blog.m-ou.se/rust-is-not-a-company/. Rust is mostly driven by volunteers working on what they find interesting. Boring/uninteresting tasks depend on funding, a warm body to accept the funding, and a reviewer.
It's not just that this is boring work, but there's disagreement about Cargo and crates.io's direction. There are a lot of changes people would like to make that get turned down.
Crates.io and Cargo need namespaces, but the leadership flatly says no.
There's a big problem with name squatting, and nothing is being done about this either.
I get that there are more technically important issues around builds and reproducibility and the like, but this is pretty foundational stuff.