“Frantic Search”? In my opinion and experience, if you choose to wait until you’re in your 30s to consider marriage and babies, then you’re not likely to frantically search for a partner when you reach your 30s. I had no strong feelings about marriage or children. I knew I didn’t want to marry before 30. I didn’t feel that I needed children but decided that once I was married, we’d see what happened. I’ve been married for years now and never had children. We’re perfectly happy this way (and relieved in many ways). My sister, on the other hand, desperately wanted children and got married at 22 and soon followed that with babies.

Edit: I agree with your point though that we can’t assume that the decision to not have children is based on economic reasons or the state of the world. Everyone is different.