The reason for this is that I wouldn't do what it takes in bodybuilding to become the greatest, so I would not be the best, so I wouldn't.
Even though it's amazingly stupid, in fighting I could do what it takes to become champion. I wouldn't throw even ONE conventional strike ever, in all of my training, for years and years I would only perfect all strikes with absolute zero windup and maximal speed, and with heavy resistance, and thus become champion. But probably at a cost psychically.
This is reality. Fighting is stupid, no matter how good you are. There are many other ways to get all of what a fighter can achieve but not even risking health. But it takes dedication.