I'm glad you brought up that yellow journalism and its variants have been going on for quite a long time, and tends to have its cycles just as most everything else does.
That said, in this day and age of instant everything, which includes the 'news,' and endless speculation and review of the events, well before there are even any facts to present, yellow news has ascended, or descended, to a whole other level. Or, at least, more of us are exposed to it nearly as quickly as it happens.
The said thing is, as you say, many people have become so used to it, that they don't know it's not truly journalism, but agenda driven propaganda with some marketing for ratings thrown into the mix.
It's absolutely true—Most news outlets are nothing more than PR firms for certain societal or political philosophies. They all seem to share the same headlines, press releases, AP news, etc., without caring about fact checking if it fits the narrative.
Never in my lifetime has a presidential election been won in good measure because the candidate ran against the media! How amazing is that? It may very well happen again.
The answer to the problem is going to be complicated, since the media is almost indistinguishable from the political parties, and those shaping society. It would all have to be dismantled and discredited, and for that to happen, I'm afraid a lot more pain and anguish is coming.
RE: How much "news" do we need?