This is why zoning reform (i.e. allowing higher density for better walkability/bikeability) is the single most important policy change to fight global warming.
From an ecological viewpoint such zoning reforms have merits, but in the way we have done it so far, I question the social merits of such policies. The society must be about more than stacking people on top of eachother.
From time to time we've seen very one-sided policies pushed (often with economical focus) and several years down the line we realise the issues of such policies. We can't afford that at this point, we need to find policies that adress the full trifecta of areas to find our way forward sustainably.
The force of these polices are applied in exactly the opposite of how you think they are. Zoning reform does not force "stacking people on top of each other;" it allows them the freedom to choose to live more closely together. Single-family exclusionary zoning is, in fact, the policy that curtails freedom the most by forcing everyone to live in only one type of housing whether they like it or not. Any property owner is perfectly free to build a single-family house in an area zoned to allow high density if they want; it's the single-family zoned areas where their property rights are infringed.
Low-density areas are objectively harmful to live in. Physical health is destroyed by the forced imposition of a sedentary lifestyle due to lack of walkability, and mental health is destroyed by the prohibition of convenient access to third places (i.e. forcing them to be miles away instead of interspersed within neighborhoods). To be very clear: this is not an opinion; this is a fact informed by studies showing that people's health and happiness are measurably worse in car-dependent places.
"Allows them freedom"? From my viewpoint, that is straight up newspeak. Which is also a point to be made, our respective frames of reference is so diverse I'm hard pressed to think we would ever use the same language to describe any form of housing. Only in America is walkability a problem in low density areas. Presuming your definition of "low density" isnt rural, of course.
And if we are rural, I have a hard time seeing how that can be defined as a sedentary lifestyle. Going for a walk is not usually a problem in those settings, either.
I live in an area where everything is roughly within a 10 minute's walk. Groceries, pharmacy, universities, hospitals, etc. It is flipping awesome. And the light rail can quickly take you to other universities, jobs and (further out) the airport.