People are often misinformed about things. Sometimes they obtain that bad information from false or misleading media coverage; sometimes that media coverage is deliberately false. And there’s a fine line between media coverage that seeks to frame issues appropriately and coverage that’s propagandistic.
All of this is bad.
Propagandistic media coverage is bad, spreading false information deliberately or carelessly is bad, misleading people is bad, and it’s unfortunate that voters (and, frankly, elite policymakers) often make important decisions operating under misconceptions.
That said, I do not think there is much evidence that misinformation has become more widespread, that this increase in misinformation is due to technological change, or that it is at the root of the political trends liberals are most angry about. If anything, people seem to be better-informed than in the past — which is what you would expect because our information technology has gotten better — and it is very hard to think of any cure for misinformation that would not be worse than the disease.