No, most polyglot codebases use Cargo. For something massive like Android that has gone so far as to implement its own build system, no third-party build system would be sufficient, so focusing on Cargo is irrelevant. The fact is, Cargo has always been deliberately and consciously designed to be merely an abstraction over rustc, specifically in order to accommodate opinionated users who would be better served by invoking rustc directly. They're following exactly the workflow that the Rust developers intended, because this saves the Cargo developers from having to perfectly anticipate every potential user's needs, which would be impossible. Rust does the right thing here.