Goku needs a new dimension of power [Super Saiyan god] in BoG.
Goku gets another new dimension of power on top of that [Super Saiyan god Super Saiyan] in RoF.
Goku and Vegeta add three years of training on top of that for the U6 tournament. Tied Hit who couldn't show all his strength.
Future Trunks arc: A new world is shown; Full power Super Saiyan Blue!
Tournament of Power: A foe who surpassed a god of destruction!
Broly arc: An enemy so strong; was estimated to be comparable to an even stronger god of destruction, in Beerus.
Galactic patrol arc: Despite never training in his life; There was no one as "tough" as Moro. Who's body's limit was angel power!
Granolah survivor arc: We face the strongest being in the universe!
Dragonball never stops adding floors to it's building.