I think a lot of the confusion comes from the ambiguity of the phrase “memory leak.” Rust is designed around preventing insecure memory access (accessing out of bounds for an array, use-after-free, etc.) and devs call that a memory leak. But another form of memory leak is just not freeing up memory when its no longer needed (e.g. continuously pushing a bunch of things to a global vector and never clearing it). That is more of a fundamental program design issue that rust can’t do anything about. (and really, neither could any turing complete language)