4 ideas
Short utterances printed with no speaker names, no framing narrative, and no chronology make the reader hear a crowd instead of individuals. Taking away biography turns each line into a sample of what a whole class of people thinks, so the book reads as the mind of 'the people' rather than a set of characters.
Presenting text as the literal words of real witnesses makes readers treat it as evidence rather than interpretation. That authority depends entirely on the claim of non-intervention. Once the recorder admits to selecting, condensing, or composing, the same sentences change from testimony into literature, even though not a word has changed.
Transcribing speech means choosing which utterances to keep, which to drop, and how to punctuate, order, and group them. Each of these choices is authorial shaping. The meaningful question is not whether a record of speech was edited, but how much, and whether the editing was disclosed.
A nurse at the Russian front wrote down the talk of wounded peasant soldiers and published it as their unmediated words. It was admired as raw, true speech about the war. Her later admission that she had shaped and partly composed the material led to accusations of fraud and set off a lasting dispute over whether the book is a document, a work of art, or both.