Agreed. TR will only focus on improving your fitness with on-the-bike workouts. Technical skills (especially for offroad riding and descending), nutrition strategies, pacing, all of those are invaluable abilities, too, but TR won’t address those, you have to add those in yourself. Ditto for strength training.
A coach can really help here relieving some of the anxiety that “cutting training hours” (on the bike for fitness) can cause.