[btilly]

Your claim makes zero sense to me. Particularly when I've personally seen similar behavior out of other languages, like Java.

As I said in another comment, the most likely cause is that temporary garbage is not collected immediately in JavaScript, while garbage is collected immediately in Rust. See https://doc.rust-lang.org/nomicon/ownership.html for the key idea behind how Rust manages this.

If you truly believe that it is somehow due to data isolation, then I would appreciate a reference to where JavaScript's design causes it to behave differently.