True, but where are the nine to stop the Daedrea. They can't...b/c the Daedra are the real gods. What i say is fact not opionon.
Short version, that's fact, sure, but only when you're standing in the right place. On their own worlds the daedra are totally omnipotent gods. However, because the Nine divines are, in part, Mundus none of them are omnipotent, but because the daedra are not at all a part of Mundus they are weaker by comparison when there, while more powerful than mortals the Nine Divines can, with relative ease, banish them back to Oblivion.