There's more to it than that. As journalism became a profession in the middle of the last century, news organizations would actually compete to be seen as the most factual and least biased sources of news.
BS.
Prior to television, ALL news sources were biased, and wore their bias proudly. Search how many newspapers have "Union" in their name.
With the advance of television, and to a lesser extent radio, it became obvious that a limited availability of transmission capability - not to mention receiver channels - that all parties involved, stations and viewers both decided impartiality was a goal worth having.
Newspapers kinda got drug along for the ride.
Now, with the internet and 1000 television stations, the -mutual- incentive for impartiality is gone, and so the actual impartiality is gone.
I, for one, welcome bias. So long as the participants are clear they're not neutral. It's a shame Fox claims to be "fair and balanced", but it's a larger shame that CNN makes similar claims.