Why Rc can't be Send?

It makes sense to me why Rc can't be Sync: it's a non atomic reference counter.

But why can't be Send? It should be safe to move a Rc between threads since that guarantees that only a single thread is mutating it.

Now, &Rc should definitely not be Send since that would be unsafe. But why Rc can't be?

I'm not sure what I'm missing here.