Mostly to have something to hold lipstick, face powder, and a cell phone and ID in. They don't want something big and bulky detracting from the outfit or makeup all of the time. I always bring my purse as I am not a fan, it's asking to get it stolen or lost they're so small and easy to pick up.
I have also thought about this before, trying to know if there was any good reason for the ladies clutching a pulse. It helps in keeping some valuables like mobiles and money when going out, and the clutch kind of give them a better look after dressing .
They do it because it's an attractive fashion variety. In my view, the clutch is more appropriate for the more elegant occasions than the full handbag would seem to be.
@kingusama92 Women would normally carry a clutch bag if they are going to an event or a night out. They are designed to carry very little whereas a handbag is designed to carry more. So a handbag is better for going to work or daily use because a woman needs to carry more atg that time. When women go out, they still need something to carry a little makeup to refresh themselves and other small items but don't want to carry a handbag. It is to do with the look of the clothes they are wearing. A handbag doesn't suit an evening dress, but a clutch bag does. They come in all sorts of designs and some are more ornate than others. It depends on what the woman likes who is going to carry it and it should match or go with the dress they are wearing. I'm not a great lover of clutch bags as I find them difficult to carry.
Just about every person you see these days is permanently "clutching" a cell phone. So I guess holding something in your hand is really not all that inconvenient for the majority of people. That said, it probably has a lot lot do with woman's clothing not having enough %&$#@ pockets. And once you have to put everything you need in a little bag instead, it makes very little difference whether it has a strap on it or not.