My first encounter will likely be the opposite, i.e. a call that will only produce a Result::Err if anything, and never a Result:Ok. I've made programs where there are a bunch of continuously running jobs that should never terminate in the happy scenario. If any of these jobs terminate, it'll be due to some sort of failure, and so Result<!, MyError> seems like a reasonable return type for such job. I think I've already used the Infallible in there but I think this being part of the language now makes the code feel more correct or clean or something like that.

And if your callers are generic over the error type, and so they do have code for handling errors, the compiler won't emit this code for your result type because you've said its error type can't exist.

Does that mean you can assign the result of the function without explicitly unwrapping? Or that the compiler removes the call to unwrap? Or neither?

You need to unwrap but the compiler removes the call. If instead you know that the callee is infallible you can also do

    let Ok(x) = call_that_cant_fail();