Putting my personal feelings about AI aside for a second …

Yes you absolutely 100% still need documentation.

• Documentation should be written by the same team writing the code, sometimes code can be left to interpretation and the original intent can help a lot.
• Documentation has a chain of custody. You can see who wrote it, when it changed and why.
• Documentation is deterministic, if you look something up you will always get the same exact response
• AI that answers your questions is built on documentation. AI cannot produce efficient documentation just based on code, it needs to be fed at least other documentation to know what it’s expected.
• Lastly AI is a grey field in the legal world. Everything in the enterprise world has to go thought risk/liability analysis. Let’s say AI gets something wrong in the docs and as a result you accidentally delete the prod DB. Who is liable? What happens with your insurance? can you be fired? Can the company sue you for damages?

Disclaimer: these are only my opinions and I’m not even a programmer. I support a dev-ops team in the field of cybersec.