As it should be, to a certain degree.
I see it as a combination of demographic stabilization and economic reality. Starting after WWI, Americans became a very nomadic people. Whereas before people lived their lives in a single state, or two, much of the population left the rural farms and migrated to the cities; there was the westward expansion, and then the great movement West to the new, post-WWII cities.
Over time, the national economy stabilized prices, and instead of seeking opportunities elsewhere, the emphasis has been to improve your life where you live. But then the post war debt oriented society has begun to spiral out of control.
Two generations ago, people graduated from college penniless, but thereafter everything they did improved their own lives. But today, graduating in debt creates a huge burden, it throws off the reproductive and success timetable. It is turning into a national disaster.
But this can be mitigated somewhat by people living with their parents. They are still delayed by a decade, but with hard work they can still get married and have children.