As absurdly powerful as Dragon Ball Super's Gods are, an impressive few characters have grown strong enough to even kill a God of Destruction.
The canon version of Super Saiyan 4 can't compete with God forms, but Dragon Ball GT's SSJ4 is borderline overpowered.
Ever since Goku first transformed into a Great Ape in the original Dragon Ball series, transformations have been a key part of every single Dragon Ball anime and manga release. Dragon Ball Z ...
Dragon Ball has since taken Super Saiyan through all sorts of new levels of power, and with it Goku and Vegeta have since broken through the ceiling to godhood with a variation of the transformation.
Only a few transformations in Dragon Ball Super are stronger than Legendary Super Saiyan, and even then, just barely.