I do think "Fake" news has become a problem, and may have affected the 2016 election, but the real news (which is supposed to be trusted) was a significantly bigger problem. Here is some of how Matthew Yglesias puts it at Vox.com:
While it’s true that fake news appears to have circulated widely in Trump-friendly corners of the internet — possibly with some assistance from the Russian government — the idea that fake news was central to the outcome of the campaign has little basis in fact. The very nature of viral fake news is that it’s mostly likely to be shared by people who have already bought into a partisan or ideological worldview, with pro-Trump fake news largely shared by Trump supporters to other Trump supporters. Clinton’s campaign did have a real news problem, but the problem was with the real news coverage — coverage that dwelled overwhelmingly on a bullshit email server scandal, devoted far fewer resources to investigating Trump’s shady foundation than Clinton’s lifesaving one, largely ignored Trump’s financial conflicts of interest, and almost entirely avoided discussion of the policy stakes in the campaign. Trump ended the campaign as he began it — unpopular and viewed as unqualified by a majority of voters, with no amount of fake news stories to puff him up succeeding in moving the needle. But Clinton, who began the 2016 cycle with reasonably high favorable numbers, saw them crater under a torrent of email stories with 45 percent of voters telling exit pollsters they were bothered “a lot” by her decision to forgo a state.gov email address, of which 86 percent voted for Trump. Whether journalists want to be proud or ashamed of the work done by mainstream press during the campaign is up to them, but it was perfectly normal stories in normal outlets that moved the needle in a major way — fake news was a total sideshow. . . . While the Trump campaign was great for the fake news industry, the implication that fake news was critical to Trump’s electoral victory seems unsupported. The election was close enough that everything mattered, so it’s certainly possible that white Catholics who were duped into believing that Pope Francis had endorsed Trump swung three crucial swing states. But it also seems clear that the impact of fake news, whatever it may have been, was minor compared with the impact — for good or for ill — of the traditional news media. A team of researchers working for Gallup found that what Americans heard about Clinton during the campaign was overwhelmingly information related to emails. By contrast, they found, “Americans' reports of what they have read, seen or heard about Donald Trump over this same period have been more varied and related to his campaign activities and statements.”
The stories about Clinton’s email server, the separate spate of stories about Clinton Foundation emails revealed through Freedom of Information Act requests, and the third spate of stories about emails stolen from John Podesta’s email account were not fake news. They were very real stories that totally normal mainstream media organizations chose to make the focal point of their coverage of the 2016 campaign. This coverage, though extremely extensive, did an extraordinarily poor job of explaining the actual legal issue at stake in the server matter. Network television newscasts from ABC, NBC, and CBS chose to devote three times as much airtime to Clinton’s email server as they gave to all policy issues combined. The Associated Press ran a major investigative story into Clinton Foundation influence peddling that treated a meeting with a Nobel Peace Prize winner as evidence of an insidious pay-to-play scheme. The New York Times did a Clinton Foundation investigation that treated Bill Clinton successfully rescuing American hostages from North Korea as scandalous. The fact that public health experts believe the Clinton Foundation saved millions of lives, by contrast, played extremely little role in 2016 campaign coverage. . . .
The sum total of this media coverage — real stories based on editorial decisions about how to weight and present real facts — was to give the public the impression that two similarly ethically flawed candidates were running against each other in an election with low policy stakes. The reporters and editors responsible for that coverage can reasonably (if a bit absurdly) consider themselves proud of the work that led the public to that conclusion, or they can consider themselves ashamed of it. But the idea that voters were moved by fake stories about the pope rather than all-too-real ones about email servers is a preposterous evasion.