I also feel like you’ve missed the point of Rey’s arc in TLJ, it isn’t about finding her place in all this or being important in general
Literal quote from Rey in TLJ: "The galaxy may need a legend. I need someone to show me my place in all of this." I really don’t see anything in the first two movies that implies she hates herself. She just seems overly dependent on people. She stays on Jakku because she wants her family to return, not because she thinks she’s unworthy of their love. She runs from Luke’s lightsaber because she doesn’t want that responsibility. She thinks Luke is the only hope for the galaxy; then, when he refuses, she says “[Ben] is our last hope.” She goes to Kylo because she thinks he’ll help them. (“This could be how we win.”) And honestly, what’s she done so far for herself? Known how to fly a ship? Anyone can do that. She was captured by the First Order. Fought off Kylo out of desperation, not by choice. Messed up big time by turning herself in to Snoke. And then she moved some rocks. Mary Sue, baby.
By that logical progression, TROS should have been about her overcoming that dependency, and learning to embrace being a hero in her own right. She’s kind of the opposite of Kylo, who spends his whole time trying to break out from underneath people. Luke, Han, Snoke…of course then he just happily joins forces with Palpy and that ruins his whole character journey but whatever. It’s two movies at least of solid character work.
The other big thing is, for all of this talk of “Rey’s arc is about heritage not defining you”… like, that’s Kylo’s whole deal, isn’t it? “Grandfather killed a bunch of people and cast the galaxy into darkness. Do you embrace that legacy or do you strike out on your own path?” Kylo’s already got that angle covered; what does it add to duplicate the whole arc with Rey?
On the other hand, if Rey comes from nothing, that’s a new twist. When you don’t have any legacy to which you are beholden, what do you do? It’s the opposite arc of Kylo’s, and you can do a lot of interesting stuff with that narratively and thematically.
It’s honestly kind of beautiful when you look at the Episodes VII and VIII without IX:
- Rey: The scavenger who has no family, no legacy. She has to overcome her dependence on others and become her own hero.
- Kylo: The child prodigy, born into the most famous family of all time. Does he follow his grandfather’s path, or his uncle’s, or his mother’s? Instead, he tries to break out and take control of his destiny, only to learn that he actually needed to embrace those around him (such as with him not killing Leia in TLJ).