From the very beginning of Dragon Ball, the appearance of Goku on Earth signaled the onset of numerous challenges. As a Saiyan with the ability to transform into Oozaru, a gigantic creature with destructive power, the story was primed for conflict. However, it wasn’t until Dragon Ball Z that the narrative took a serious turn.
Regardless of Goku’s heroic intentions, we cannot overlook the fact that his very presence attracted some of the most formidable threats that Earth has ever faced.
Therefore, aside from being a hero, Goku can also be viewed as the central character responsible for the chain of catastrophic events that unfolded thereafter.
Raditz and the Beginning of Hostile Encounters

It may not be fair to blame Goku for the arrival of his brother Raditz on Earth, but we cannot ignore the fact that his presence opened the door to impending conflict. Each new encounter did not merely mark a new chapter; Raditz’s arrival also paved the way for the emergence of other powerful Saiyans like Nappa and Vegeta, who brought with them devastation and destruction.
Frieza and the Series of Violent Confrontations

Speaking of formidable foes, Frieza cannot be overlooked. This iconic villain has challenged Earth numerous times, all fueled by a desire for revenge against Goku. After suffering defeat on Planet Namek, Frieza sought to settle the score, leading to even greater chaos with each subsequent appearance.
The Arrival of Cell and the Reality of Majin Buu

When we look at the character of Cell, we realize that his existence is a direct consequence of the actions taken by Goku during his battle against the Red Ribbon Army. In the Cell Games saga, Goku faced several pivotal decisions that forced him to make sacrifices, including allowing Cell to absorb a powerful opponent to elevate the stakes of their battle.
By the conclusion of the Cell Saga in Dragon Ball Z, although Goku sacrificed himself to save the world, he was later resurrected by the Dragon Balls. After this, Goku acknowledged that he was indirectly responsible for the series of attacks that besieged Earth.
As for Majin Buu, this formidable threat only truly manifested its destructive capabilities during battles involving Goku, Vegeta, and Gohan. Without Goku’s presence, Buu might have never reached its full potential.
The Consequences of Goku’s Actions in Dragon Ball Super
In Dragon Ball Super, Goku bears direct responsibility for nearly all the threats that arise on the planet where he resides. His selfish desire to seek out stronger opponents often leads to catastrophic consequences for the universe.
Not to mention Frieza’s return to Earth seeking revenge after being resurrected, which led to the emergence of even more powerful threats capable of endangering the universe.

Lastly, we must not forget the significant arrival of Goku Black. This character is essentially an evil version of Goku, existing only due to Goku’s own existence.
When Future Trunks returned, he brought news of a dark version of Goku. This character from the future was revealed to be Zamasu from Universe 10. When Goku learned of this, he eagerly wanted to join Whis and Beerus to investigate Zamasu. The encounter with Goku influenced Zamasu to create a plan to eliminate Goku.
Source: Animerant