However, instead you're referring to documenting as a few smart people stand in front of a whiteboard for a couple hours and sketch out the details. That is a valuable activity. Just remember that within a couple days you need to erase that whiteboard because it's useless anyway. These days I would use an LLM to help me create that, especially if it's a part i work on alone. However, it's only a help and I understand again that this is a guide to get me started but it won't match reality and so I'm not going to share it with others.
To give some context, I've been working remotely since the start of my career and transitioned to a more content-oriented role last year, so I never progressed beyond being a junior engineer. But I do remember the deep discussions and technical planning sessions being the most rewarding and mentally challenging.
I have seen that AI has the same tendency of over-engineering solutions when you are in the documentation phase, where it tries to scope out the entire plan before I have a clear idea of what I wish to do. So I typically begin with a simple markdown doc and disable auto-complete before reaching out for it later.
If the document it to be useful it needs to be kept up to date. You can never go more than a couple hours of coding without updating the document. Every change will take half again longer than before because the documentation is part of the change. Everybody who reviews the code needs to also review the documentation change. Every other developer must read (not to be confused with review) the change as well so they know.