Exactly, I don’t know how big that place was in modern context, but from what my mom said the home had doors on opposite sides of the city block and upwards of 20 people lived there from ages 1-90.

The key term is delayed adolescence. Having a 19 year old that has a job, does their own laundry, pays their own bills, etc is different from someone who is still on mom and dad’s insurance and phone plans, not paying rent, and not buying groceries.

As an example, at 25 I was working full time and my boss was 10 years older than me. My car insurance went up and I was complaining about it to my boss. Overall he didn’t think it was a big deal, but the next day he came in and told me that our conversation had got him thinking. Turns out his parents were still paying for his phone bill and car insurance. A 35 year old man living on his own and his parents were still paying his fucking bills and, icing on the cake, he wasn’t aware of it.

My mother’s family was similar to this a few generations ago, 4-5 generations used to live in one house in Midwest USA. Their home spread from one city block to another. That said, I cannot imagine living in a <2500 sqft home with my parents and my significant other. My SO would go Thunderdome on my Mom and my dad would be freaking out on the sidelines.

I have a coworker who is engaged, he lives at his parent’s place and his fiance lives at her parents place. As someone who lived without my parents (even if it meant having roommates) since 18, I cannot at all understand long term living with parents.

Communal family living was a thing in the past because modesty, temperance, and christian values were expected norms. If you want to be a puritan, or don’t have familial shame, then do whatever you want. For me, I’m gonna have my privacy and peace.

PS: My coworker can’t spend the night with his fiance because her parents are mega religious. He can either sleep on the couch or go to his parent’s place. Likewise, his parent’s won’t let her stay overnight at all because they aren’t married.