Regular Python bindings / c extensions don’t depend on a pypi-packaged instance of gcc or llvm though. It’s understood that these things are provided externally from the “system” environment.
I know some of it has already happened with rust, but perhaps there’s a broader reckoning that needs to occur here wrt standards around how language specific build and packaging systems handle cross language projects… which could well point to phasing those in favour of nix or pixi, which are designed from the getgo to support this use case.