I once asked ChatGPT to write something, but I played a bit with the prompt. Then I copied the text directly into different ChatGPT-detectors, and none worked. :D
Apart from that, I've heard that some detectors say that US constitution is AI-generated.
Nevertheless, I agree that copying directly from AI is bad. AI is a useful tool to help you, but it's not someone who will do your job for you. I use Perplexity.ai all the time for internet research, for example.