People like generic cliche stuff with overpowered MC. Why do you think Solo Levelling is popular? It doesn't matter if the characters are bland as Western's food, if they can self insert to the plot.
If it makes you feel better, the ratings on novel updates is just low AF maybe because the people there have critical thinking.
The MC is supposed to be smart but she just plagiarizes her sister's ideas to gain affection. Many times and many times. There's no creativeness, just copying what her evil sister did and BAAM, she beat her sister. I never read a villainess as lame as her but we as the readers have to understand because she just paying back what her sister did. In fact, she's a Mary Sue in villainess setting.
I very much agree with you. They lack creativity and the story is pretty linear; there's no complexity to it. As for Solo Leveling, it's really the art style that's saving them otherwise I don't think the story itself is appealing at all, esp with an MC who never lose and is too OP.
I gave it a shot cause of the positive reviews, but it's quite cliche. Cliche story, boring plot, unlikeable characters. Regardless, I can understand someone liking this if it was their first villainess manga, but I've read plenty and this is one of the less well written ones.