I hate how self-centered the FL is, she's literally the textbook of merry sue

I agree. Shes literally has never done anything wrong in her life. But thats what a lot of FL leads are, they have a pitty sad background and she has never done no wrong, she was so nice and could do no wrong. No flaw.

That’s why I enjoy villainesses manwhas like, roxanna, kill the villainess, and death is the only ending for the villainess (?). The female leads of these stories aren’t Mary sues