The Wonder Woman movie did what to Steve!? [SPOILERS]
To the point: they made Steve Trevor likeable and amazingly relevant. Chris Pine made me root for the man every time I saw his stupidly attractive face on screen fumbling and respecting Diana in every which way and being patient, made me love the budding feelings between them because I’ve just never seen that before with his character? Or with him and Diana in general? Okay, the Justice League cartoon came pretty close, but context was different there.
And before I get into anything else, this is going to get SPOILERERIFC, so do keep reading at your own discretion.
I will definitely argue that his relationship with Diana is essential. Maybe not in their romantic relation, but what he represents for man, and the world outside of Themyscira, and what it inevitably leads Diana to place her trust and her goals in.
Steve is not just a potential love interest for Diana, he is the reason why Diana comes to love the outside world and believes in Love itself. In essence, he represents all the good that mankind has to offer in the face of violence and war, and will always try to fight the good fight because it is what he believes in. He loves the horrible world he lives in and tries to make it better in any small way he can, because when war comes, “You either do nothing, or you try something.”