I’ve got this theory percolating that 1) mass cultural/behavioral changes happen due to changing needs, 2) those needs tend to sit discomfortably unmet or undermet for awhile before either a new option appears or the discomfort of enduring overcomes the discomfort of rebelling and then significant changes are made, and 3) conservative forces become their own enemy by failing to acknowledge, respond to, and accommodate changes in the status quo and make things worse in their attempts to preserve that part of the status quo they can see.
In this case, part of the issue is that living with parents/family as an adult can interfere with one’s sense of independence, one’s freedom, and one’s privacy, and strict behavioral norms (that sometimes get stricter over time and with increased economic prosperity (this is a whole thing)) become first annoying and then infuriating to the point where one might prefer living in a car if it meant you could come and go when you pleased and wear what you wanted. And so there’s a rebellion, and people create both their own separate living spaces AND their own behavior standards, which calcify over generations into their own strict standards and develop their own problems and, at the same time, slowly become untenable as the profit motive exploits every opportunity, capitalizes on every excuse, and shakes down every margin it can find.
It looks very much like we’re in an end stage of the nucleated way of living, with our options for avoiding it limited by economic circumstance, zoning, and cultural conventions to the thing we most previously escaped—adult children living with their parents. And the pandemic has only turned the tension up, in multiple ways—socially as well as financially, as standard means of socializing outside of one’s household have been cut off by quarantine procedures, to say nothing of the existing generational political differences.
As to what will happen, that could go many ways. I think the ideal result would be a downgrade in housing size, complexity, and cost, as demand for something simple and affordable meets the realization that for most of human history people have been living in small, simple, often handbuilt structures and now we have electricity, indoor plumbing, and better insulation materials to improve on them; also ideal would be social groupings of multiple households to form an unhierarchical “found family” variant of the standard extended-family model. However, all of this will face stiff resistance from entrenched building, zoning, rental, and real estate interests, and it will probably take drastic measures like large percentages of the population “choosing” tent cities over apartments they can’t afford, or unapproved sharing of single-family houses with multiple adult roommates, for sufficient pressure to reshape the social environment by which our definitions of acceptable means of living are held.