Certain applications have different levels of randomness, but the chatbots are usually put on higher levels of randomness, especially the entertainment ones.

You can make something that produces the same output every time. This is more commonly used for code autocompletes. So if you try to chat with Copilot, you'll likely get something more deterministic.

ChatGPT is probably toned down more than most, to avoid it from going off the rails. It is a bit sad that the AI most people have access too is rather "caged". The "jailbreak" techniques actually show AI closer to what it's like. Saying ChatGPT is deterministic is similar to saying a human in a call center is deterministic; they're following a SOP but that's not what they're really like.