[Expurple]

> you can still ignore the return value

Only when you don't need the Ok value from the Result (in other words, only when you have Result<(), E>). You can't get any other Ok(T) out of thin air in the Err case. You must handle (exclude) the Err case in order to unwrap the T and proceed with it.

> It also litters your code with branches, so not ideal for either I-cache or performance.

That's simply an implementation/ABI issue. See https://github.com/iex-rs/iex/

Language semantics-wise, Result and `?` are superior to automatically propagated exceptions.