This completely misses what valuable code documentation is for. Anyone can read the code and figure out what it does, what as a documentation can be convenient,

This completely misses what valuable code documentation is for. Anyone can read the code and figure out what it does, what as a documentation can be convenient, but it's not really all that useful, especially if it rots over time. Even if it's painful at times, the what is all there in front of you in the code. Valuable documentation explains the why, why was one approach chosen over another, why do we need to do this to begin with, why are the edge cases the way they are. This information is not present in the code and no tool can ever extract it since it isn't there.