1. Do you often try to implement data structures like this? In my practice, arrays are almost always better. 2. Beside that, you may argue that I use "Don't have therefore is not required" argument. But it contained partial truth: if you fight Rust program model then you have to do some extra steps to achieve it. Rust borrowing model considers one owner who can share its data among consumers. And this is damn common situation. I written a whole telegram bot with futures, using Arc container only once, to share my http client across the threads.

If you fight GC in Java then you have same troubles: all this stuff like weak pointers, byte array storages, reflection, etc, etc... If you are trying to write imperatively in haskell... And so on. If you fight language ideas, then your code becomes more complicated. The answer here is that you shouldn't have to do it often.