I've heard as a possible explanation before that LLMs are mainly trained on long-form written texts, whereas more colloquial speech (spoken or in text chat form) typically uses simpler speech. So, where normal humans would put "Sure!" or "Yeah!", the LLM will likely write "Certainly!", because that's more likely what's written in a blog post.

Alternate title: Generation that venerated disregarded books reading for the first time

edit: omg for some reason I thought venerated meant dislike (it means the opposite!!). This is what happens when you're given books at too young an age folks. You pull fancy words out of your ass cuz they vibe right. But you risk realizing that you probably inferred the wrong definition from wherever you learnt it.

I think people's vocabularies got worse as they stopped reading. While irritating, this is nothing compared to that.