Why is Bollywood obsessed with replacing female actors in franchise films like Baaghi and Singham?

Dabangg, Baaghi, Golmaal, Singham and Housefull -- what would you say is the most common factor among all these films? Yes, on the surface, they are all mega Bollywood franchise films which have gone on to make crores of rupees at the box office. But they also have one other thing in common. A constant change of female actors with each new film. Bollywood has a track record of boosting the male ego by portraying an actor as the man of the house, a provider or larger than life character.