Asuka wanted to have sex with Kaji because she wanted to affirm her individuality and emancipation from her childhood. Moreover, everyone wants to have sex with Kaji.
Meanwhile Rei is actually going through a similar process, she's also coming to terms with her individuality and desires. Her character development is far more than "i can feel", which is just a ridiculous interpretation. She's always felt, and always had a strong emotional bond to being a pilot. Her character arc is about her acquiring agency over her feelings and actions, which culminates in EoE.