As a former linguistics student, I can say that you don't understand your chosen subject very well. Formal linguistics studies the mechanics of language & speech, but all that is just to give people a foundation to help them understand the important (and interesting) parts of the linguistics field: the areas touched on at length in this video.
Whether a sound is classified as a voiced bilabial fricative or an unvoiced bilabial fricative doesn't have any intrinsic signficance or importance. The significance of the classification is so that linguists can have a common (and well defined) set of terms to discuss the important stuff. It's a shame that so many linguistic students (and even professors) think that the classifications themselves are the point.