So I’m watching through the show and I’ve now gotten into season 3. I really liked season 2 and thought that Sara was a big reason for that. However I felt that things ended with a lack of closure with her and her family, and more importantly Oliver.

She decided to breakup with Oliver because she seems to feel like she’s broken and will only cause him pain. Throughout season 2 it honestly seemed the opposite to me, and I liked Oliver and Sara’s relationship. She leaves then comes back with the assassins for the final battle which made it make some more sense. However I don’t believe there was a single real deep conversation between Oliver and Sara at the end of the season to give them some closure about their relationship, and a final goodbye before she left.

It felt a little too open of an ending to me when a large part of the season was exploring their relationship in both the past and present. It wasn’t a big deal because I expected her to show up and figure this stuff out in season 3. Well she definitely shows up! And then dies lol. Very unexpected for me. So my question is what changed so fast? She seemed to be fitting well in the team, going along well with Oliver, and it seemed they were setting her up to be his primary side kick. Then in the matter of like 7 episodes she leaves him, leaves entirely with so many remaining open wounds and unresolved relationship issues (not even just with Oliver), then they kill her off. This is like if they just killed Laurel off right at the beginning of season 2.

Maybe I shouldn’t be asking this until I finish season 3 but I’m very confused about what caused them to do this.

Maybe I don't understand timelines. However we see in the pre crisis timeline in the flash forwards that Star City is in ruin and horrible place to live in and that is a result of Oliver's death. But he still died in the Crisis timeline anyway so how does that change the fate for Future Star City where it is a place of no crime and peace?