Fwiw, we can have that moment of completion (for lack of a better phrase). But it's usually not after as long period of incongruity, and that does make comparison difficult.

As an example, a lot of young cis people have to discover what being their gender really means, how they are going to fit themselves into their gender. It's definitely not as broad an experience as what I've seen and heard from trans people, but it is certainly a similarity to use for finding understanding.

Because we don't have that sort of impossible to self realize barrier that trans people have, I don't think the sense of completion will ever feel as powerful, and I agree that it isn't a truly comparitive experience. For us (me) it's more about expanding into a realization of the self that's balanced between external expectations and internal pressure.

I can remember the first time I became aware the fact of trans experience. It was confusing, and I've made errors over the decades in seeking understanding. It's one of those things where you try to truly empathize, as well as gain intellectual understanding, and it takes steps, a series of enlightenments to get closer.

Which is a long winded way of saying that there are more similarities than most people realize, but that you're right that when cis folks do figure out the similarities in experience it can, and will, lead to better understanding.