we would not actually know how and why either CSAM or heroin or burning plastic is bad and affects victims/drug users without actual studies involving their impact. you cannot just from-first-principles every single possible issue.
It is absolutely bananas that one of the most prominent anti-AI experts in America is talking like this. Talking to ChatGPT isn’t like doing heroin or downloading child porn. It will not hurt you and has no ethical valence. It will help you understand the nature of something that is now endemic.