Dragon Ball Daima proved that Vegeta has been able to tap into SSJ3 for some time, but there are other forms fans don't ...

Super Saiyan 3's Specialty Is Its Untapped Strength In Dragon Ball Daima Episode #12, titled "True Strength," Vegeta is pushed to his limits by Tamagami 2, who overpowers even his Super Saiyan 2 form.

Super Saiyan 3 Is Goku’s Strongest Form Right Now Dragon Ball Daima is set shortly after the events of the Majin Buu arc, and before Beerus and Whis arrive during the Battle of Gods arc.

Goku might not be defeating Gomah all on his own, even with this form making a comeback. At this point in the Dragon Ball timeline, Super Saiyan 3 is how strong Goku is able to go.