Most deadwood implies a lot of unnecessary or inactive material that is not productive or useful. Antonyms for this phrase could include "active", "productive", "efficient", "purposeful", "significant", "valuable", "essential", "fruitful", "meaningful", and "contributing". These words suggest an opposite state of being, where all parts are actively contributing to the whole and are required and appreciated. While "most deadwood" suggests stagnation and inertia, its antonyms indicate that everything is thriving and optimized, creating an environment where purpose and progress are the norm.