I realize that you’re referring to traditionally-typed text, but Monotype was recently commissioned to design a typeface for the illustrator of Roald Dahl’s books, and they did indeed include alternates for each letter (along with variations in kerning):
>…He selected four subtly different alternates for each character that, combined, would make the text look random enough to look authentic while keeping the glyph set manageable
My parents' handwriting was borderline illegible, so they took to typing letters on a manual typewriter. Typewriters suffering from all the problems of complex finicky mechanisms, and being a write-only medium, resulted in a pleasing quirkiness that is completely absent from email. Read enough typed text, and you begin to recognize a person's particular "hand" at the typewriter, as well as the machine's individual quirks. Electric typewriters put an end to most of that, and email finished it off.
My parents' handwriting was borderline illegible, so they took to typing letters on a manual typewriter. Typewriters suffering from all the problems of complex finicky mechanisms, and being a write-only medium, resulted in a pleasing quirkiness that is completely absent from email. Read enough typed text, and you begin to recognize a person's particular "hand" at the typewriter, as well as the machine's individual quirks. Electric typewriters put an end to most of that, and email finished it off.