I doubt you would ever blurt out a copyrightable portion of a book without realizing that's what you're doing. That's the biggest difference.

In particular, you are a legal person who can be sued in civil court if you infringe on copyright. If I ask you "can you help me write a blog about Manhattan?" and you plagiarize the New York Times, then the NYT sues me for copyright infringement, then I would correctly assume you conned me, and you are responsible for the infringement, and I would vindictively drag you into the lawsuit with me. With LLMs it involves dragging in a corporation, much much uglier. Claude is not actually a person and cannot testify in any legally legitimate trial. (I am sure it will happen soon in some kangaroo court.)