The politics of the written word

How does narrative differ from stream-of-consciousness?

You believe they are the same.  When they are not congruent, one or the other has been jostled aside by the author, attempting to butt in line with some observation or other with the justification that the reader has to know.

Readers are not so sure about this.

In much the same manner as the author, a politician from any layer of the political spectrum will justify behavior in the name of the American public.

Constituents are not so sure politicians know who they're talking about  when they refer to the American public; they are in fact not sure what politicians are talking about much of the time, their cautious and self-exculpatory tropes causing frustration for their constituents.

Readers are not so sure they need to have the reader appearing in front of them to explain things, to lead them through the labyrinth gardens of narrative.  You've come to conflate Readers with Constituents in terms of the relative degrees of frustration each demographic has to experience, Readers emerging a tad ahead of the game because they can always set the book down and leave it down.  Constituents have to wait sometimes as long as six years to get the satisfaction of voting against an incumbent senator--even then, such satisfaction as can be had is likely to be only in the vote as opposed to the unseating of the incumbent.

When you edit, you try to edit the author out of the narrative, keeping it where you feel most comfortable with it--in the control of the characters.  This makes it easy to suggest stream-of-consciousness as an anodyne for that boring sense that pretends to objectivity but which is in actuality linear recitation of detail, woeful and noticeable in its lack of sensuality.

When you write, you take effort in revision to keep your opinions to yourself, instead permitting "them," the characters, to advance the lines of action and response, each to the others.

When you read, you notice passages, chapters, even complete works wherein the writer agrees with the approach you use or is successful enough to be allowed egregious lapses of editorial guidance.