Katherine's character has many different aspects, more than elena's.

^ Elena's character has many different aspects too. The reason everyone loves Katherine more is because they find her more interesting (that's at least how I see it, I may be wrong).
I personally love Elena. She's my favorite female TV character. I know many people don't like her because they find her boring and annoying, or simply Stan Damon/Stefan to the point they hate her every time she isn't absolutely nice to said brother. I personally find her character very realistic. She's someone who has to deal with a lot of emotional trauma and loss, and she still finds ways to be happy, is still there for everyone she cares about and manages to go through the day, even with all the weight on her shoulders. I love that her character is flawed. She isn't perfect like some people on the show or the premise and synopsis of the show imply, but non of the characters on the show are perfect. I just wish the fandom wouldn't jump on every little mistake she does and demonize her.
Not that I don't like Katherine. I really love her, especially this season. She's the only character on the show that currently has a well-written storyline.

^ i agree with you. Elena is my 2nd favorite female on the show.

Love both though!

my favourite tv female<3