Rust does not require GC-less memory management. It supports reference counting out of the box, and reference counting is a kind of GC. It's not inherently any harder to use than Swift (another memory-safe language) which plenty of average developers use to code for Apple platforms.
I don’t think it’s a useful observation. Lots of people come to Rust from OOP languages and try to make everything `Arc<dyn Interface>`, and it immediately fails, to their great frustration.
It's fine as long as the graph of references is immutable, or is unidirectional/acyclic with unique ownership.
If you have backreferences or "parent pointers", you need `Arc<Mutex<...>>` or `Rc<RefCell<...>>`, and then you run into trouble as you encounter the same node multiple times while traversing the graph, because you cannot hold a mutex lock or mutably borrow `RefCell` twice in the same call stack.
The solution with much less resistance in Rust is to go for a data-oriented representation. If you really need an actual graph of objects, separate the node data from the topology metadata, and refer to the nodes using an ID or index. (As an extra bonus, this also gives you much better cache locality.)
