Rivalry is a cornerstone of shōnen anime. The clash of characters in both power and personality helps to create a natural sense of tension in relationships as they build throughout a series. Some of the most beloved characters in anime tend to be the rivals of the protagonist after all. My Hero Academia's Katsuki Bakugo has managed to secure the number one spot in the popularity polls for almost as long as the manga has been going. One Piece uses friendly rivalry as a way to keep the entire crew motivated to get better and better. Sasuke Uchiha basically became the secondary protagonist in Naruto despite being the rival that ended up defining the character trope for much of the early 2000s.
Source：https://www.cbr.com/goku-vs-vegeta-who-actually-won/
