I mean, if the conclusion is "you shouldn't assume that JavaScript code is free of memory safety problems", that's absolutely true. JavaScript is a memory safe

I mean, if the conclusion is "you shouldn't assume that JavaScript code is free of memory safety problems", that's absolutely true. JavaScript is a memory safe language, but the VM that executes it, and the native code that it binds to, can have bugs that punch a hole in the theoretical model. But your takeaway shouldn't be "memory safety isn't valuable because memory-safe languages can have bugs". Empirically, programs written in memory-safe languages have far fewer memory safety problems than programs written in non-memory-safe ones do.