Seems like there could be a convergence of the demographic trend of millennial family formation with pandemic related increase in people's perception of the value of square footage that is pushing people toward that classic Single Family Home housing product.
Problem being of course is that they're not distributed in the right places.
Of course the era of normal people without incredible levels of wealth owning a detached home in cities like SF, Seattle, etc is long over. There will only ever be less and less SFHs as these cities urbanize further.
The market urbanist solution to this issue has been to build more housing, and more apartments, townhomes and duplexes with larger footprints that are suitable for a family, so that one wouldn't need a detached home for a larger family to affordably live in one of these big cities.
That we're seeing people abandon certain urban places may be a sign of the failure of those governments to actually get any of that product sufficiently built, but it also could be a sign that, despite similar square footage, people don't see townhouses/apt housing product as the same sort of value as a detached house, and they are willing to make remarkable life changes to own a fee simple house proper.