Right. Kyusho/Qin-na and so on are skill sets, not styles unto themselves. Their techniques are used within the context of a compatible style (one whose movements are designed to facilitate their application.) Pressure point skills cannot be used by themselves (unless the opponent is a sitting duck.) A bullet is not useful or efficacious by itself - it needs a firearm, a delivery system. The particular martial art style is the delivery system for kyushu.
Before an effective pressure point or joint lock attack can be applied, the user (and opponent) must be in position and the opponent must usually be weakened, distracted, injured, or immobilized to some extent. The style provides the method by which this is accomplished. This method, as Koryuhoka states, is illustrated in the style's kata - whether or not the practitioner or observer recognizes this is another matter. This is where kuden (oral transmission) comes in as these skills were closely guarded in Okinawa and not clearly shown in kata.
Since many pressure points are protected by muscle, bone or tendon, the opponent must be manipulated so as to "open up" these areas, exposing their vulnerability. This is why it is important that kata be performed as originally intended, and with proper form. Going off track here will render the following subtle pressure point/joint lock attack (as well as takedowns, throws and other good stuff) to be ineffective. But many sensei/students do not even know this stuff is built into many traditional kata.
One doesn't need kyushu (forget about the magical BS seen on you tube) or joint attacks to be a good fighter, but they can certainly give a 5% boost (potentially much more) to the effectiveness of one's abilities. And, when chance delivers the opponent in perfect position for one of these techniques to be applied, it will be a much enjoyed gift.