Where did you get that impression? The creators of Rust would undoubtedly love that to be the case, but Rust is still essentially in its infancy. To my knowledge there are almost no major projects released that have been built in Rust. It's ranked below such heavy hitters as Ada and Prolog for popularity on the TIOBE index[1]. It's pretty unlikely that Rust will become the standard language for everything crypo- or security-related anytime soon (or ever, but it could happen).