Comments that say HOW commonly useless, as that is almost always self-evident (i.e. "just read the code."). Comments that explain WHY are worth their weight in gold, and not something AI could ever create.

For example:

    // How: This filters records by MyType of J and if they have children   
    // Why: We want Jobs (J) when those Jobs have Children. Otherwise, we'll get JobGroups or Jobs without any Children we need to process below.   
     .Where(T => T.MyType == "J" && T.Child.Count() > 0);  

WHY are, by their very nature, business rules or explaining a thought process. If the original developer of the code moves on or is unavailable, that information can sometimes not be found elsewhere.