You know what I've noticed about people who stutter, alot are very pessimistic. It may not address the mental side of stuttering but it definitely address the physical side cuz we stutter physically due to lost of breathing control. Techniques that focus on breathing are the ones im talking about. People who stutter hold their breath during speaking due to anxiety and anxiousness, i stutter too and i realize i stutter as do so many others is cuz we speak with lack of correct breathing.... but maybe you're right and a percentage of stutterers don't stutter from lack of basic speaking mechanics( i highly doubt that) so kudos to you and anybody else lol. Me personally cuz i know my body my stutter is definitely due to lack of proper breathing and i get this cuz i still have that stutter anxiety from time to time. I went from from stuttering very severely to the point i couldn't say a single sentence to practicing daily and speaking alot more often mildly. But like i said, to your point only you know if techniques work for you and thats your personal experience so I have no right to say otherwise. Btw i don't use the term "techniques" cuz the ones i practice are are basic necessity to having normal speech