As for when this fully automated future arrives, I don't know, but I don't think LLMs get you there. More and more boilerplate code, and even novel code, might get written by things like Codex. However, all the messy details of real world systems solving fairly intractable problems need something more akin to, if not AGI, then another type of AI. I might be wrong, I just don't feel that threatened by ChatGPT / Copilot based on what I've seen. It's an amazing technology but weirdly underwhelming for my job. Copilot etc will change things, but replace us? No.
Of course, something else may be just around the corner so I'm not complacent.