My two cents is that advertisement is what is killing journalism.
YouTube, for example, can show advertisements for well known companies in videos about Anti-vaccination, far-right conspiracies, etc. without consequences.
Why is that? Because all that happens in the privacy of your own computer. Usually any newspaper that publicly have printed such bullshit in their pages will be dead. Public will react to it.
What is different? Facebook, YouTube, etc. are personalized. You are shown what you are interested in without public accountability. Niche radical content gets a lot of views for its own controversial nature. Views and money.
Who wants to investigate, hire good writers and expend the money that it takes to write a good article when you can hire some one without ethics for a fraction of the price and get as many or more views as radicalization grows?
YouTube, Facebook and others say that they are not responsible of the content they offer. I think that it should be true for things like comments. But for the monetized content they are 100% responsible of incentivizing that radicalization and killing good journalism in the process.