Ever since Goku bested Vegeta at the end of Dragon Ball Z's opening arc the Saiyan Saga, the Saiyan Prince has obsessively sought to surpass his old rival for much of the subsequent story by any means necessary. While a burgeoning friendship between the two men has since been borne from this bitter rivalry, Vegeta has worked diligently to become the universe's strongest warrior for a long time.
As Vegeta and Goku's adventures continue into the Dragon Ball Super manga series, it is clear that Vegeta will never exceed his longtime frenemy's power level -- but given the exact nature why, it is probably for the best.
Over the course of Dragon Ball Super, Goku and Vegeta were both trained by Whis, the angelic attendant to Universe 7's God of Destruction Beerus. This imbued both fighters with divine energy that, combined with their natural Super Saiyan abilities, led both men to be able to transform into Super Saiyan God and Super Saiyan Blue. While Goku attained a serenity in combat that led him to master the Ultra Instinct transformation, Vegeta's potential was increasingly linked to that of the God of Destruction itself. This led Vegeta to achieve the powerful Ultra Ego transformation, rivaling Goku in power as the two Saiyans faced off against the villainous Granolah for the fate of the universe.
For Vegeta, Ultra Ego allowed him to tap into a power he had craved his entire life, fueling his strength through his sheer love of combat and raw fury -- and potentially endangering those around him while he maintained this state. However, Vegeta realized could not sustain his newfound transformation. The responsibilities and dedication that come with tapping into the unfiltered power of a God of Destruction would cause him to reprioritize his life, to abandon his growing family and the life he had built since becoming a Z Fighter during Dragon Ball Z. This is a distinction that sets Vegeta apart from Goku, and for the better.
While Goku certainly loves his family and has largely been there for them since his resurrection near the end of DBZ, he also loves the thrill of combat and his own martial arts improvement above all else. Goku has been known to leave his family for prolonged periods of time to selfishly focus on his training, and has even endangered the entire universe to take on the deadliest opponents imaginable.
The biggest example of this was during Dragon Ball Super's Tournament of Power, with Goku suggesting a martial arts contest between the different universes at the risk of Universe 7 being completely erased from existence. This would persist at the end of Dragon Ball Z, with Goku and Uub leaving Goku's family behind so he could train the young boy for the explicit purpose of giving himself a worthy opponent.
Goku's heart is ultimately in the right place and, for all his faults, he is a hero and family man -- but not in the way Vegeta has steadily become over the years. While Vegeta came back to Earth striving to exceed Goku and resented his burgeoning family for getting in the way of that goal, he has come around to genuinely care for his wife and children, unwilling to leave them behind and achieve the power he long sought. While this may cost Vegeta any chance he had of permanently surpassing Goku, the Saiyan Prince has finally accepted this concession as well worth the new priorities he has embraced in his personal life.
