All news has a bias, some news just doesn’t tell you what their bias is. I’m not advocating for intentionally aiming for biased news, I’m advocating for knowing what the bias of the author/editor of the story is, so that when you read it, you know what conclusion they might be trying to lead you to. Even if a journalist tries their best to be impartial, that’s not possible, and like I said, it’s very easy to tell a one sided story with exclusively facts.
It’s also useful as a visual notice of a parenthetical comment.