This is a shortsighted statement. Diaphragmatic breathing works but its requires hard work and skill to use it properly. And its by no means an easy task as we’re dealing with fear. When we encounter a very strong blocked word nothing really works, to be able to breathe from the diaphragm that too a strong breath requires a lot of focus to execute properly. Kinda the equivalent to a soccer player trying to hit a shot from long range very quickly lol. Theres not much time to think and you have to be accurate. Hope that makes sense