> The most important cost that you didn't mention is the loss of social trust and the harm that will do to social infrastructure.

This. I think generative AI will mostly generate destruction. Not in the nuking cities sense, but in hollowing out institutions and social bonds, especially the complicated and large-scale kind that have enabled advanced civilization. In many ways, things will revert to a more primitive state: only really knowing people in your local vicinity (no making friends online, because it'll be mostly dead-internet bots out there), only really knowing the news you see yourself, more reliance on rumor and hearsay, removal of the ability for the little guy to challenge and disprove institutional propaganda (e.g. can't start a blog and put up some photos and have people believe your story about what happened), etc.