Rapid prototyping is almost a meme at this point. If you are hand rolling code old school, you will waste more time shoehorning JavaScript and python semantics into rust code and end up with worse quality that takes more time rather than writing it from rust.

People did this a lot when rust was not as popular but there are plenty of very good rust programmers now who understand the language and can make programs that are significantly more performance for a marginal development cost.

Script ability can also be done in rust, Notably Zed (rust ide/vscode whatevers) is written in rust, and all the plugins are compiled to WASM, sandboxed and loaded.

Go is pretty nice for server-side API but if your application share types between boundries then rust is better

Rust is great for rapid protoyping, IMO. Or, at least the subset of rapid prototyping that involves massive rewrites to try out different approaches. Rust has a saying "if it compiles, it works", the compiler really ensures that you don't miss something when doing that rewrite.

My employer company go through JavaScript, Java, Golang and at the end landed on Rust for srver side and don't want to change anything. Everything is Rust now, regardless of traffic.

I don't know why you think it's only usable but this is your right.

GPU programming?