How does Sonakshi, Parineeti and Sonam get female-oriented movies?

Is it because of the lack of options? I know Sonakshi and Parineeti are better than Sonam, but even they fail to draw in audiences. Then how come they get so many chances? Is it because of nepotism? Or are there such limited choices to play female-oriented roles?After all, Deepika, Kangana, Alia, Priyanka, Anushka and Vidya are there, and they have better star-following too.

Sonam got 2 movies this year, Sonakshi 1, and Parineeti has the Girl on The Train and Saina Nehwal biopics coming up. Do they really deserve such roles, considering their box-office standing?