Throughout the course of their entire Dragon Ball careers, Goku and Vegeta have done nothing but strive to increase their power levels through rigorous training and intense battles with a number of increasingly deadly foes. However, while fighting one particularly powerful enemy, Goku and Vegeta learned that they will never be able to reach the strongest form a Saiyan can take.
Since Goku first broke the barrier of what was believed to be possible for Saiyan warriors by unlocking Super Saiyan during his fight against Frieza, Vegeta has always been one step behind him in his own upgrades. In their most recent chapters, Vegeta has all but caught up with Goku as both have unlocked Super Saiyan God/Blue and each of them are working towards mastering separate yet equally as powerful god-like forms with Goku perfecting Ultra Instinct and Vegeta channeling Ultra Ego. Even when channeling the powers of gods and angels, Goku and Vegeta will never truly be divine as they were born mortals, something that is holding them back from reaching an incredibly powerful form.
Related: Dragon Ball Super's Strongest Villain Teased the Return of Future Trunks
In Dragon Ball Super Chapter 20 by Akira Toriyama and Toyotarou, Vegeta and Goku have traveled to an alternate future to battle Zamasu and Goku Black. Weirdly enough, Goku Black is Zamasu from another timeline who swapped bodies with his universe’s Goku and thereby took the Saiyan’s powers for himself. Zamasu was a Supreme Kai-in-training, meaning that he is a literal god within the Dragon Ball universe, making the essence within Goku Black divine in origin. After battling Goku and Vegeta, Goku Black realizes he needs to push himself even further than he already has to match the power
Read more on screenrant.com