If you’re a guy, then you don’t realize how many totally essential items women have to carry in their purses. A small suitcase might do it, but she’s compromising and carrying a purse, for appearance’s sake...
I'm married, so I know how many "essential" items my wife carries on that sort of trip. My thought was that anything that big should be in a suitcase, but she does have different demands than my wife faces. She may have to change outfits far more often than I'm used to, just to reduce criticism that she was too casual, too formal, or too whatever.
I’ve had the same purse for over 15 years. It’s not big, but it’s packed with stuff. It doubles as a lethal weapon because of its weight. Just as good as a lock, or a can in a sock.