In general, if everyone is rewriting their JavaScript code into Rust, maybe they should ask themselves why they are using JavaScript at all outside the browser.
By way, this used to be how Javascript related tools for browser deployments were written before nodejs became a thing.
Because they don’t want to write Rust, especially not for applications, but they don’t mind if someone wants to implement their tools in Rust.
Did this need to be said?
The language you might use to speed up a build tool has little to do with the language I might want to use to build most software I write, especially the application layer.
They are rewriting the build tools, because the NPM ecosystem produces a bloated mess of multi megabyte bundles out of the box and you have to re-bundle from scratch during development every time you change even a single file.