Well, of course, it didn’t apply to me. I moved into apartments that were shared by other women.
But to show you the other side: I have a very wealthy, somewhat naive friend (21 years old!) currently residing in a beautiful apartment on Madison Avenue paid for by her family. Her boyfriend moved in rather quickly - using the place only as a pit stop. So, it works both ways - depending on who has the green stuff.
Of course it happens both ways, but it is more common for females to move from the family home, to the boyfriend’s home, to the next boyfriend’s home, to the next boyfriend’s home.
One of the depressing things for a man to realize as he reaches into his 20s and late 20s, and his 30s, is to realize that the “girls” that he is running into, have never lived on their own, they were never the single girl of the Mary Tyler Moore sitcom, living on their own and dating, instead they merely move from one man’s apartment, into the next one, their love always involves a residence.