If this Dawn is legitimately a hero, then she probably holds herself back from her max power level in order to avoid collateral damage, much as Paul does (Iron Legacy isn’t any more powerful than regular Paul, other than having armor on; he’s simply more willing to use what he has to its fullest extent, so heroic Dawn would be the reverse).
In general I figured this universe had to be facing massive epic-level threats, with Omnitron and Voss being two of the major candidates. Nothing unifies the human race like an existential threat that comes pre-dehumanized, by virtue of being an alien or robot or zombie or something.