Many spells, weapon and class abilities scale off of Weapon Damage. If Flawless Dawnbreaker buffed that stat, its bonus would be HUGE.But that's not what it does. It just makes light and heavy attacks
But right now, Dawnbreaker is all you could ever want <img class="emoji" src="https://forums.elderscrollsonline.com/resources/emoji/smile.png" title=":)" alt=":)" height="20" /> Even I as a magicka Sorc use dawnbreaker.