Not joking, buy and read books. Old books are only written by people. (and the help of an editor)
The immediate reply to that comment is: "On the internet, no one knows you're an editor." This is a direct play on the famous 1993 New Yorker cartoon: "On the Internet, nobody knows you're a dog." By setting the anecdote in 1987 (a few years before the World Wide Web was publicly available), the commenter is implying that back in the analog days, if a dog wanted to be a writer or an editor, they couldn't hide behind a screen—they had to sit in a smoky London pub and do business face-to-face.
Which makes a lot of sense actually. I would imagine that's what the replier to you thought you meant.
Both magazines and books are valid forms of information consumption and books are not the only way to improve your writing, reading, and understanding of the world.
If you limit yourself to stuff from maybe five years ago or older, yeah it's going to be human-written and human-edited (ghostwriting still possible).