One of the benefits of some common GC algorithms is how efficient it is to allocate (for most allocations), meaning the GC overhead is small and possibly negati

One of the benefits of some common GC algorithms is how efficient it is to allocate (for most allocations), meaning the GC overhead is small and possibly negative. I don't think comparing the (throughput) performance of doing allocations is where Rust wins in a convincing way: any major benefits come because the language makes it easier to avoid them totally, as you imply. In any case, the most common things people clone when learning are strings and vectors, where cloning is an O(length) operation (allocation plus copying the data), which doesn't avoid any allocation overhead and I would think counts as computationally expensive. (Notably, in managed languages with immutable strings, Rust's copies are significantly more expensive, since the former can copy in O(1).) Cloning is definitely a perfectly good way to get started, but it shouldn't be dressed up as something it's not nor should Rust itself.