Because we add humans enjoy variety. I read for entertainment, even technical posts like this one that I have no use for. I often trying to think about what the author may have been thinking when writing, why they introduced concepts in a specific order, what ideas might they have omitted, etc. It's personal and enjoyable. But now, when I detect the familiar writing style of what seems to be a gpt 5 model, that "parasocial" connection dies.

The LLM explained the core concept and features very well. But it was dull and boring to me, as I already have to read this writing style at work pretty much all day every day.

I hear you, and agree with your points, but do have to ask - what’s the point in complaining? See LLM slop as you called it, ignore it and move on. There’s plenty of more intimately authored content out there.