Put simply, if people are confident when they think they are right, and if their confidence makes them persuasive, then this may help us to identify what is true.
However, I think people have different perceptions of what "confidence" is. Trump doesn't always seem genuinely confident to me. Overbearing, insistent, aggressive, and more, but he's also whiny and insecure, at least in my view.
Unfortunately, for some, simply yelling seems to be a signal of "confidence".