It’s not so simple. Many couples don’t work in the same place. You could have the wife working in city A. And the husband working in city B 30 miles away. Moving to where they work only works for one and not the other. In other cases they have kids and the school districts in large cities are absolute shit. In that case you move for the school district so that your kids can have better chances in the same rat race you are in.
Unfortunate that the sprawl is so heavily subsidized. In a world where it wasn't, people would make different choices about where to live and work.