I can't speak to LLMs, but one of my first tasks was debugging a race condition in a piece of software. (I had no idea that it was a race condition, or even what part of the code it was in.) I spent months babysitting the service and reading the codebase. When I finally fixed the issue the source turned out to be a comment that said the opposite of what the code actually did. The code was a very convoluted one-line guard involving a ternary if / several || && statements. If the comment hadn't been there I think I would've read the code sooner and realized the issue.

Personally, I remove redundant comments AI adds specifically to demonstrate that I have reviewed the code and believe that the AI's description is accurate. In many cases AIs will even add comments that only make sense as a response to my prompt and don't make any sense in-context.