One simple but ill understood way in which this is true is in the numbers of people interacting within a group or institution. In drama the audience can keep in mind only a set number of major actors - even in a relatively complex political procedural, at most a dozen characters will recur. In reality, the humblest institution may have dozens or hundreds of regularly interacting people who take active part in decision making. So the implicit and unintended myth created by all films and television diminishes the importance of the collective - with its web of loyalties and contrasting intentions - and replaces it with a tiny number of easily tracked isolates. Character motivations always need to be personalised in drama, with 'complex' motivation existing to humanise rather than explicate action.
There are countless other examples of the ways drama systematically distorts our understanding of life and politics. From the disavowal of the motivating force ideology and (even in the United States) religion, to the systematic concealment of poverty.
None of these necessarily require censorship or explicit manipulation. They're not simply expressions of a particular societies blindness to its own flaws. But exemplars of what can easily be transmitted in drama.