There’s also just plain, old-fashioned psyops. When the entire media community is telling you something, and you have no unbiased information readily available, you tend to believe what you’re told.
Which is why the US government continues to allow the news media to consolidate itself to a small handful of mega-corporations, because the larger a company is, (a) the more influence they have over policy and (b) the more invested they are in the status quo, thus, they can be seen as reliable mouthpieces for government propaganda. And [c], the smaller the group is that has to get together and agree on a theme, the more likely they’ll stick to it.
Which is why every news organization marches in lockstep regarding what they will and won’t cover in terms of news. All of the takes are the same. Jeff Flake is lauded as a great speaker of truth to power, when in fact he votes with Trump 100% of the time. The DNC pushed the narrative that Trump was a serious contender, and Bernie was a sideshow not worthy of coverage, so news organizations slavishly covered every word Trump uttered, and blacked out coverage of the massive crowds Bernie was getting for months.
Did you know there was a major lawsuit filed against the DNC due to their manipulation of the primary? Most people don’t, because there was virtually no coverage of the trial. Even though the DNC lawyers used the bombshell defense that, So? So we manipulated the primary. We’re under no obligation to the voters to conduct a fair process. That seems newsworthy to me, but it wasn’t in the news.
Why do people believe stupid shit?
Because of confirmation bias — they believe what seems like their perspective, and use cherry picked pieces of information to confirm it.
Because that belief benefits the political goals of some entity in power.
Because it is easier than thinking for yourself. Also, because many people aren’t confident enough in their knowledge of the topic to speak, thereby ceding the floor to those with an agenda.