I think you have to have some sort of dysphoria to be trans, otherwise what is it that makes you trans? I don't think it has to be constant or crippling though. A lot of people think dysphoria is hating your body, but it's not. It can be, but that's not all it is. A lot of people think they don't have dysphoria until they learn what it is, and then they realise these things they've been feeling for so long, it's dysphoria.
For myself, I'm quite confused. I have dysphoria, but it's often very mild, and I don't know if it's naturally mild, or if it's mild because I avoid almost all situations that I know make me feel bad. For me, I never even already felt like a guy. I'm always scared to say that, because I'm scared it invalidates me being trans. But I'm being honest. I didn't grow up thinking I'd go through male puberty or anything. I just often felt like I wanted to be, or should've been, a boy. That's still how I feel, because I feel like I've been built using some wrong pieces that have been forced to fit. And I can be that thing even with the wrong pieces, but I don't have to be, and I don't want to be. I want to be me, like I'm meant to be. To some people, that means I'm not trans. A lot of people have their own definition. There just has to be a reason why you're not cis.