To be fair, the novels targetted at straight women do this too with handsome men. Though, I prefer the protagonist to be on the cover.
The worst is when I see a title and it says something like queen of darkness, but the protagonist is a male. Come on!
A protagonist not being on the cover is a red flag to me. It lets me know that the story will have a generic/boring MC.
What do you mean I have to read until chapter 100+ before the girl in the cover appear in the story???
Not because one of my stories doesn't have the protag on the cover, but so far every story I've read with a big titty busts of their characters on the cover have been mid or written like by middle schoolers.