I think that if you have a game/DCC/whatever app you write in Rust, being able to also write any shaders it uses in Rust is simply nice.

And as an added benefit it means not adding another language to a project and all that comes with it for build system/CI. I.e. cargo takes care of everything. That alone is worth a lot IMHO.

Apart from that its not related to Rust. Just replace Rust with your fav. language and imagine you could also write shaders/GPU-targeted code in it. Isn't that desirable?