Rust doesn’t have namespaces in its package management system. It’s often viewed as a bug. But it’s not a bug, it’s a feature! While there are negative aspects of a flat package registry, there are also real benefits. Stability, continuity, and unity (discourages forks and fragmented identity). Proposals that seek to add namespacing without addressing the positive aspects they remove probably won’t be accepted.
I have noticed the benefits of the current system seem to only get mentioned in passing as objections to proposals and never outlined anywhere.