I think you can also document in a way that is also up to date. For example, do you document the who/what/when/why for version commits? Sure. Do you put in-line comments in the code, e.g. "We need to revise the code below at some point to account for ABC"? I hope so. Do you have a stash of reference scripts/how-tos so you don't have to reinvent how to do semi-routine complex actions, like deployment? What about an active system to keep track of to-dos, priorities and who they are assigned to, what happened, how they were accomplished? Even email history can be effective documentation.
Otherwise, I would agree that documentation in the form of a bulk document which is probably already flawed at 1.0 and easily outdated is mostly a waste of time. (Past the mental exercise of the person writing it, perhaps.)