I think ChatGPT's programming prowess might be a bit overblown. A majority development efforts are spent in adding functionality to existing code , fixing bugs and reducing technical debt. I am not sure ChatGPT can do this.
Only for arbitrary reasons. ChatGPT is entirely capable of being provided a block of code and then answering questions about it or making modifications to it. Without the token limit and with some way to guarantee that the code you provided won't make its way into their training data, this would be an entirely reasonable use case.