Is hypnosis or hypnotherapy useful to overcome a phobia?
Yes, hypnosis is a great tool for releasing phobias. Phobias are not usually logical, but you can't just talk/ logic yourself out of them.
What works is to explore how this illogical phobia got established in the first place. Hypnosis is excellent for finding the origin of the phobia and releasing it on that deep sub-conscious level.
Whether it's a fear of flying, of elevators, of spiders, of public speaking, etc. - hypnosis can help you make the change you need.