Dresses like that aren't worn every day by average women, but on average, women wear dresses like that every day. If that made no sense, what I'm saying is that given enough women, dresses like that are worn every day by one of them. Since you can't rent a dress more than once a day anyway, an overall every day seems like enough. It doesn't matter if everyone wears dresses like that all the time, only if at all times, someone is wearing a dress like that.
While it's a cool concept, I can't see it being more than a novelty long-term. Dresses like that aren't worn every day.