Why not just adopt?

I've really never understood the lengths at which couples will go to in order to get pregnant. I don't mean I don't understand wanting to have children. What I mean is, why spend thousands and thousands of dollars to maybe get pregnant. Not only are the odds bad, the cost exorbitant, but also there are moral implications of the un-implanted fertilized embryos. Why not just adopt? I get that it's not always optimal, but what is? Kids need parents, parents need kids, it's a win-win. People make it way too complicated.

Plus, ladies, your body will remain unstretched, which is nice.