Why can't we, A villain have a Happy Ending?

A woman from the 21th century got reincarnated in her favorite novel called ‘loving you unconditionally’ after finding out she was reincarnated into the second villain named “scarlett rina o'hara” to escape death; she decided to have a Happy Ending. By helping the main villain Luciano to have a Happy Ending despite being rejected by the female lead numerous of times.