I view it as two different things. You need sources of input to stimulate your own thoughts. Historically, talking to others, reading other works, etc. I can see a chatbot as part of that tradition.

But in your own mind, your thoughts are still incomplete. The act of writing them down (or, I imagine, in an oral tradition somehow committing to a specific narration) is very important. IMO, when you delegate that to an LLM, you are not really thinking. It's the same as if you explained your ideas to someone (eg in an interview), and then they ghost wrote the work for you.