As she told Variety, the science fiction genre allowed her to stretch her creative legs by playing characters who mattered, had agency and were heroes important to the story versus just being generic archetypes and forgettable supporting characters.
Instead of being a down-on-her-luck Latina in every film, science fiction opens up a whole universe of possibilities to play with.
Plus, it has to be cool to play aliens, assassins and other characters who have been memorable, important and interesting in these imaginative and expansive worlds.
On the road to stardom, Zoe Saldana turned down roles that she saw as typecasting, so you can see how the science fiction genre gave her an opportunity to do different things than plain dramas or comedies might afford her.