Battle of Gods proved there will always be someone out there who is stronger when he struggled so greatly with Beerus.

Goku learns many moves throughout Dragon Ball, yet his use of Hakai in Dragon Ball Super makes zero sense for multiple reasons.

The threat of Majin Buu has passed, and Goku and friends are all living in peace. Then there appears Beerus, the God of Destruction. The story finally moves beyond the universe, into a new phase!