Karate was never created for sport fighting. Only rarely did adepts challenge each other, never enough for a clear record of which instruction made a difference. Karate was a means to retain a group cohesion within am Okinawan Samurai society, an upper class. One you had to be recommended for then work to obtain permission to train within.
Your training depended on your instructors whim. Which does not mean it was not whimsical, just it was dependant on what the instructor chose. It was not standardized and could change as the instructor wished for whatever reason he felt was needed.
When it was introduced as a school activity it went further changes. Those training in the group may of may not have followed the public curriculum. Then more changes. Karate-ka began sharing training openly (it certainly happen before, but in more private settings, consistent with earlier karate tradition. The public curriculums began to enter the group practice.
The War happened. Many seniors were lost. After the was the surviving karate-ka took their training and forged newer traditions, and karate kept changing. Then the disporia occurred and the world took over with different traditions. Each claiming they were the older tradition.
Karate changes made many assumptions. For one thing explanations for movements became a new tradition. ‘Bunkai’ became formalized. Not enough trained long enough. What were simple answers for beginners, became the standard. Not enough time was spent understand how individuals learned.
Kata is after all just a template. The possible interpretations are incalculable. Buy when they became a fixed practice, the mind started to accept that was the answer. Most stopped at that point having an answer for the movement. This was a very different potential.
People forgot the purpose of kata study was acquiring skill, without developing those skills in movement you could not make those bunkai work. Then perfectly reasonable answers looked as they would not work. In turn individuals choose to look at different answers that would work, and not often enough would the root execution be seen as the answer.
Of course there were different answers, many times good ones.
However, the fact that it takes on the average 10 years of practice to gain adequate execution of one kata movement (and only adequate at that), and another 10 years on each subsequent kata does one recognize the true picture. The reason isn’t magic, rather after a decade or so the performer relaxes during execution. Then the muscles being relaxed cause one’s center to drop and the power during execution to increase. Power.
Along with subsidiary training , also in decades, adding power and skill.
Only at that time does the study of applications become critical. Where each move can be used in many different ways. Incorporating various mechanical force enhancers. Does Kara the infinite become understandable. It is a truly vast body of knowledge, but one with a specific purpose. To increase understanding to understand the underlying principals.
Which cannot be read, but must be experienced. Over and over. Whether the number of kata be few or be many matters not. The unending practice and study is the matter. Not to understand every movement in each kata, that is but a surface study. Rather to understand how to make any movement work no matter the attack it faces.
This science of entering any attack and selling whichever movement you choose and make it work. This is what the goal is. This understanding is not prone to shortcut study. You need to prepare the body and mind through your training to be controlled through your intent or spirit.
Many means exist for vastly shorter training for the sport of karate or other endeavors. They are what they are, hardly karate.
Karate was originally a way to set a class apart from others. A binding force to improve life, not to fight, but to live.
Karate correctly done, still is.