How could it be unsafe? Well, if you ask it how to deal with a grease fire and it recommends pouring water on it, that seems like it would be unsafe. Or perhaps you hooked a Python script up to the output of ChatGPT and let it call API functions that control a robot arm; that could also be unsafe. It doesn't seem like a crazy thing to worry about.
I'm not sure what you mean by "by itself" – at the very least, the comments section here is always filled with humans who say they find ChatGPT useful. I haven't personally found it very useful yet, but Copilot certainly is, and it's very similar to ChatGPT in terms of architecture.