What did GDS Darkseid do? He absorbed Mordru, which was impressive for sure. He mind controlled 3 billion Daxamites, also impressive as hell. He did all this to conquer the universe. He failed though.
Hal, on the other hand, succeeded in destroying the entire universe and was in the process of remaking it when he was finally stopped (by the Spectre).
I don't see how the latter could be considered the lesser feat noneermm