For me the worst is when it offers to summarize the latest chats with friends. Um, no. I am talking to people I like. I want to read all 57 messages in this thread; that's the point. Even if I've been away for two weeks, AI doesn't know what I think the important bits are.
As both an academic and a writer, I am repelled by the "this looks like a long document. Would you like me to summarize it for you?" that seems to appear at the top of every pdf viewer now. NO. The *entire point* of good writing (either books or journal papers) is that every sentence has a purpose.