It's true for new projects. For rewrites (such as a shell) it can mean a lot of regressions. The rust-replacements for coreutils are a good negative example. The new programs do not reach feature-parity, added regressions, and in some cases also had security vulnerabilities.

So for battle-proved software I wouldn't say so per-se (if your goal is to replace them).

Nonetheless, if you add truly new rust-code to a new or existing codebase when it's without much of hassle with the interop it should hold.