alt Hacker NewsOr read magazines and newspapers from reputable publications. My grammar and writing have improved tremendously from reading quality magazine articles, e.g. stuff from The Atlantic or The NY Book Review or whatever.
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.
I wouldn't count on current stuff in those publications being free from AI. We're seeing it in peer-reviewed paper submissions so why not in literary forums?
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).