I think what you laid out is a strong foundation for any kind of struggle and would equate in success more often than not. I think another aspect is expectations. Some people achieve 50 percent improvement and are very content with that. And their others are who achieve 95% improvement and will never be content. I knew someone who stutters and we were friends for about 5 years. I never doubted his stutter, but I may have heard him block a handful of times in those years. Yet, someone who was very mild, he dealt with it the worst I have ever came across. It led to immense self loathing, constant catastrophization, alcoholism, job unsatisfaction, and it went on and on. He could never see the positive in anything. The man must have tried nearly a dozen different stuttering programs and it was always "I'm not the problem, they're the problem. Noone can fix me and everyone hates that I stutter" . A very toxic person to be around after a while.