As the first villain in Dragon Ball, why did Tenshindon gradually become cannon fodder?

When Charouk is defeated by Gohan, you can see Tenshindon telling you that it may never see you again. Tenshindon, why do you say that? It is entirely because Tianxintang can't keep up with Wukong's pace. If the enemy becomes stronger and stronger, Dan Xintang's staying alone will only drag down Wukong. So Tenshindon left the big army. That's why we can't see Tansington in Magic Man Buo.

Dragon fans should have discovered a problem long ago, that is, many of the earliest characters in the Dragon Ball gradually became walk-ons with the development of the plot. But they used to be equal rivals with the Monkey King, such as Tenshindon with three eyes. You should remember that in the earliest martial arts chapter, Tianxintang was the Monkey King's biggest rival, and the only person who could rival the Monkey King at that time. He created a lot of awesome moves at that time, such as Sun Quan, Qigong Gun, and body separation, but it was such a figure that he gradually became a role that was not even cannon fodder. Are Saiyans too strong? Or is the person with three eyes too weak?

At first, Tianxintang was also a strong man, because Wukong couldn't beat Tianxintang at that time, and finally Tianxintang won the first Wushu Association championship in the world. This shows that Tenshindon was very strong at that time. Later, because of the appearance of Bick devil, Tianxington turned his back on the darkness and fought against Bick devil with Wukong and others. At that time, in order to defeat the Bick demon, Tianxington learned to seal the wave, but in the end he failed to seal the Bick demon. But from this time on, Tenshindon can wash white.

I met Tianxintang at the first martial arts conference in the world. At that time, Master Roshi used Tianxin, so Wukong and Tianxin were hostile. At the world's first budo conference, Tianxintang also discounted Yamcha's leg. According to this situation, Tianxintang belongs to the strongest villain of Wukong. But why did Tenshindon become soy sauce in the end?