Could I see your sources for how Rust is slower for iterations?

I've been working in JS, Python, C#, TS, and F# for about ten years. I'd guess F# and TS are tied for me for prototyping speed. I have to wonder how much the "common knowledge" that strongly typed languages are slower for prototyping is driven by unfamiliarity with the tool.

I didn't say anything about strongly typed languages being bad for prototyping. I specifically said Rust is bad for prototyping speed. Lots of high profile cases of Rust being abandoned (Witchbrook comes to mind as an example).

There have been lots of posts here about Rust being not the nirvana it's claimed to be for such projects. This one comes to mind https://loglog.games/blog/leaving-rust-gamedev/

I say this as a big fan of Rust. I use it for CLIs, microservice development and more. The borrow checker, traits, enums, etc. are amazing for maintainability, reliability and speed. Fast iteration where you'll want to completely redo a system at the drop of a hat? Rust is a royal pain in the behind.

Largely, proponents of Rust who push it for game development have their minds stuck in the solutions space and forget about the problem space. The fact that Rust was even proposed to fix Eve here is a huge example of solutions focused thinking (bad bad bad) because is misunderstands that Eve was never bottlenecked on processing speed of its physics or business logic.

Depends on what you do. For prototyping GUIs without well-defined framerwork, Rust is terrible. TypeScript wins completely. For back-ends, not so clear, since it is easier to write the intent there and even prototype must be somewhat correct, and TS is not as explicit as Rust is.