If you've only looked at two or three languages that not coincidentally happen to do things pretty much the same as each other, and not looked elsewhere, then you are indeed disregarding other languages.
> and reinventing the wheel
I didn't mention reinventing the wheel.
> I'm not sure what words mean anymore.
Agreed, but i'm not sure i can help you with that.
If so, that's interesting, but then my question is why we didn't make use of that.
That being said, Cargo would also have to understand it, because the Rust language does not understand namespaced external packages, so you'd either have to change the language, or change Cargo to do something to paper over that somehow.
As for "why didn't we do this in the first place with crates.io", https://internals.rust-lang.org/t/crates-io-package-policies... lays out some of this background, though not all of it.
> When we looked at package ecosystems without namespacing, we found that people tended to go with more creative names (like nokogiri instead of “tenderlove’s libxml2”). These creative names tend to be short and memorable, in part because of the lack of any hierarchy. They make it easier to communicate concisely and unambiguously about packages. They create exciting brands.
I will never stop admiring your ability to see the bright side of things.