Maybe I'm mistaken, but I don't think it's a Nostr problem specifically. I don't go to other social platforms, except for some group chats, but I do see AI art in so many real world non-Nostr places these days. The group chats are also full of it. But it's all expected given that most people always loved horrible premade meme images before AI was a thing. Also people talking to AI chatbots are a thing worldwide, or so I'm told. It's hard to imagine but I do believe there are millions of people who just open ChatGPT and have long conversations and find them interesting.