Not really, Rust can be 1% of the codebase but by Rusts nature it is implemented the most critical paths.
Rust is insanely awesome for embedding. So you can have Python app that 90% of your team works on and embed Rust for the critical parts to optimize.
But I get your point, however Rust is one of the most discussed programming languages in the past year on HN so it must be doing something right.