I think using refcounting can allow you to get lazy with your object graphs, throwing referencing to objects around everywhere and then losing the ability to conceptualize who owns what and who is responsible for who (so to speak). Sticking to a stricter ownership graph forces you to be more deliberate with how your types are designed and this can lead to better architecture in the long run.

Agree. I think for the limited scopes such as in a mod/function, using Rust's borrow checker semantic makes sense as it is easier to fit in our mental model. If you have to pass those data structures around to the outside of your limited scopes, I would prefer Rc/ARc more. I also think the style guide has a catch all phrase there when it says "OK to use Rc/ARc depending on the complexity...". For me, having to pass a shared reference around is enough complexity to reason about.

I find using lifetimes to be simpler and easier to follow than reference counting, unless you're in a situation where you actually need a shared lifetime.

Adding Rc/Arc is just another layer of indirection and noise that makes the code hard to read.