While this is I’m sure true, the main point is about knowledge transfer. New people come onto the job, and they need to learn how to do it, and their skill leve

While this is I’m sure true, the main point is about knowledge transfer. New people come onto the job, and they need to learn how to do it, and their skill level will always be basically zero. The question is, how do they learn how to do it, reading books or having a mentor watching over them? Certainly having a mentor will make that far easier, but if all the people who knew how to do it are now retired or especially dead, this isn’t possible, and so it becomes considerably more difficult for a new person to learn.