well that's partly true. well do know what brain areas are causing stuttering or correlate to stuttering. Examples like basal ganglia, brocas area, Wernicke's area etc.. We know also that the amount of white matter in some parts of the brain in people who stutter is less when compared to fluent ppl. There's just a ton of progress in the research in regards to stuttering within the last 10-20 years and we can expect it to increase with the advent of AI and speed at which tech is developing. Saying we don't know anything isn't exactly true. Now I agree that we still don't know why these brain areas are behaving in a way that lead to stuttering and how they developed to be so. But I think within the next 10-15 years or less, stuttering will be solved due AI assisted drug development. I think I heard that the chinese just found a way to turn cancer sells into pork cells or something thus making the tumors benign. So if they can make such progress with cancer, it's only a matter of time for stuttering.