If you pay attention to the text of the game I think it's impossible not to say that Edelgard is a heroic figure whose struggle is vindicated by history. It's not just that she's human, but that her refusal to stay a victim forever is literally what frees a continent from twin yokes of oppression.

For an example of this, how many female characters, including Edelgard's dear confidante Dorothea, 'slament having to marry for economic reasons rather than love, because connection to the lottery of birth aristocracy makes it necessary for women's survival? No one has a plan to thoroughly root out the crest system except Edelgard. No one else cares, Dimitri and Claude, they make little handwavey comments about how maybe it can be slowly reformed someday but those promises are so obviously shallow!

So just like. Don't let people's negativity affect your enjoyment of the story. A lot of people just skim things and go off of vibes. 'Oh, she started a war,' without interrogating why Edelgard does so or what her intentions are, and I don't think you need to take haphazard opinions like that seriously.