Curing and moisture content

I have read the many archives on curing and have a question about moisture content.
Zandor mentioned adding a fresh picked leaf to the curing jar if the buds become overdried. This is too add a small bit of moisture back into the buds. Why is keeping a small bit of moisture in the buds important? Does it have to do with how it will burn, taste, THC degrade or something else entirely? Is this just a preference or is it necessary to keep buds from becomming over-dried?

No different from really dry tobacco that crumbles like dust.
It's just poorer quality in every way. It'll taste worse, some THC will evaporate etc etc etc
It would be interesting though, if someone could devise a method where you can completely dry it out into a powder for storing purposes, and then just add moisture 5 years later and it springs back into life.