Why Rust has so much marketing power ?

Ruff, uv and Polars presents themselves as fast tools writter in Rust.

It seems to me that "written in Rust" is used as a marketing argument. It's supposed to mean, it's fast because it's written in Rust.

These tools could have been as fast if they were written in C. Rust merely allow the developpers to write programms faster than if they wrote it in C or is there something I don't get ?