Bias in itself isn't bad, its when someone tries to hide that bias that it really becomes an issue.
I think it's usually worse than hiding bias, I think a lot of people don't recognize the implications of their own bias enough to try and hide it. Even if people see their own bias and acknowledge it, they often treat it like "yes, that's my opinion" and don't understand that they might be ignorant of other perspectives.
I've gone on this rant a couple times, but I do like repeating myself so I will. I listen (and yell at) NPR pretty frequently when I'm driving. I don't think many would dispute that the people doing news for NPR lean left and are aware of their bias, but they attempt to present unbiased news. And all due respect, they really do try, they will have people on with all sorts of points of view and give them basically identical treatment. But it's not equal because the NPR voices are utterly ignorant of Republican or otherwise right-leaning positions. You can have a perfectly identical interview format with two people that goes as follows:
Host: I'm here today talking to so-and-so.
Guest: Hey, thanks for having me on.
Host: So you're involved in XYZ. Can you tell us more about that?
Guest: Sure, yada yada yada.
Host: So what you're saying is...
And here's where the interview diverges, when the host tries to rephrase the statement to help the audience understand. Because if the guest is left wing, the interviewer already understands the guest's perspective thoroughly, and their restatement will be spot-on, and the guest responds "exactly". If the guest is right wing, the interviewer tries to do the same thing but genuinely doesn't understand and rephrases it wrong, and the guest has to go "well no, that's not it." Even with unprejudiced equal treatment, the bias still hurts the segment, as the guest's perspective is more poorly represented and the conversation seems to become combative just because of ignorance.
Having a bias, as in an opinion, is inevitable. Being forward with what that bias is, I agree is good. But anyone who wants to present actual fair news is obligated to try even harder to understand the things they disagree with before presenting them, or their reporting is tainted.
And right now, basically all news sources at a national or global scale suffer from not only failing to understand those the disagree with, they don't even have friends they disagree with to ask.