My wife and I are both professionals at about the same income tier in industries with a lot of hiring overlap. If I get a nice job offer somewhere far away, I can't just go home and tell the little lady to quit her job because we're moving somewhere for mine. And unless the offer is truly great, we can't just make the leap and assume she'll find an equally good job after we move. We pretty much have to plan this stuff out together or stay where we are, which is why we're paying more to live in a place with a lot of job opportunities in a lot of directions nearby. We can change jobs without selling our house or dragging the other person through the job hunting process.
The days of, "drop everything and move for a new job" had more single income households that could devote all of their planning energy to optimizing for that one job. And even then, moving for work tended to be moving from a low population area with few employers to a higher population area with more employers.