When SW was written, the intention was that Luke and Leia would ultimately end up together (simply because that’s how these kinds of stories usually work). Saying that she’s immediately “dismissive” of Luke but “instantly intrigued” by Han is an incredible misrepresentation of what happens. She’s immediately dismissive of both of them, but quickly comes to respect Luke while the same cannot be said for Han. What you’re seeing is simply that Leia happens to have more chemistry with Han.

When they wrote ESB, they clearly noticed this, so they decided to add the Han/Leia romance with a strong love triangle in mind. This was prominent in early drafts and deleted scenes. When it finally came down to it, and the film was trimmed to what it is with extraneous bits removed, we ultimately have a movie where Luke expresses no romantic interest in Leia and vice versa, only one scene where Leia kisses Luke to make Han jealous (with any other romantic context for their kiss completely left out on the cutting room floor).

So in the end, yes, the love triangle never manifested. SW very lightly suggests that Luke and Leia might be a thing, but in the context of the next two films, it is much easier to ignore this and focus on Leia and Han’s bickering, which while not romantic in the original became such in ESB (which retroactively make them seem so in the first film).

Inbreeding never had anything to do with it, and thank god that one poster who always talked about that hasn’t popped up in a very long time.