I have an owner in Manners Class that says the best thing her dog gets from training is Confidence.
Confidence can make a fearful dog calm:
It enables dogs to relax around other dogs, other people, and new situations:
It may even make a reactive dog into one that takes life in stride. (If you have ever dealt with a reactive dog, this is HUGE.)
Years ago there was a saying, “What! Me Worry?” If you want a “What! Me Worry?” dog, get it into a positive training class ASAP and look for good changes as your dog gains confidence from training.