Without the stability of both parents taking care of kids at home, once the last child leaves, probably 50% of the parents will get divorced within 5 - 10 years.And I think a lot of the parents had anxieties about their kids moving out too. (Not sure why; I look forward to being an empty nester!)
I grew up in a suburban bedroom community of working people next to the city over 5 decades ago. Parents wanted their kids to have as good or better life than them and most kids went to college. Most parents were sober, stable, married, both employed, and kind... like the Cleavor family only poorer. My Dad after getting out of Army/Air Force/WWII built our home himself on 5 acres of partly wooded yard land he bought in an idyllic setting with a creek running across the end of it. It was pretty much surrounded by woods owned by the stone quarry, farmers, and others. Kinda like living in a campground so we had no interest in 'going camping', that was home. Although my Dad also built boats that we took to the lake. The nearby city had 5 major auto factories paying good wages and employing tens of thousands of people and similar large factories making other things plus supporting businesses. The city also has several colleges. The major one with 2 campuses: a 4 year and up and a 2 year. The 4 year has dorms and fraternity houses but most students are commuters. The 2 year has no housing and most students are commuters. The other colleges were mostly commuter except for nursing schools. I went to college full time (less than full time got you drafted into War on Vietnam if you were a male) and worked full time over night, studied the rest of the time, ducked back into home to get what sleep I could. Still ended up in Vietnam later. Back in my day, part time jobs for students at large employers paid about the same as full time jobs, but now they've been cut to 1/2 - 1/4 of that pay. Probably because of outside competition from Asia.