My wife is renting a maternity dress for her baby shower. This is really smart, because that is a dress you will likely only wear once.
But, here's the reality. MOST dresses are dresses women only wear once. Because you're crazy. And you think that the world will judge you with contempt - even if you wear it to two separate weddings that have absolutely no overlap of social circles.
Maternity dress rental makes sense. But so does dress rental of every kind. The only reason this business doesn't explode is because or irrationality.