Yes, all the time. Yes, those go to production. AI has improved significantly the past 2 years, I highly recommend you give it another try.

I don't see the behaviour you describe, maybe if your impression is that of online articles or you use a local llama model or ChatGPT from 2 years ago. Claude regularly finds and resolves duplicated code in fact. Let me give you a counter-example: For adding dependencies we run an internal whitelist for AI Agents; new dependencies go through this system, we had similar concerns. I have never seen any agent used in our organisation or at a client, in the half year or so that we run the service, hallucinate a dependency.