Why couldn't Akira Toriyama let Korin pick up one win instead of Goku?

During early Dragon Ball series, Korin was said to have higher power scaling compared to Mercenary Tao who was training to beat Goku and Goku was doing the same thing against him too, but with Korin more often. Why couldn't Akira Toriyama just let Korin defeat/kill Tao instead and still went with Goku being the ultimate hero?

Goku took away too much spotlight from other characters picking up wins against major villains.