i know multiple developers with public dollars to build housing $800k-$1.2M per unit. so i don't know, maybe come up with a better solution I'd be happy to hear your idea that is realistic and will deliver more units at a lower cost.
[Edit] I am serious. Homebuyers dont want to pay US construction prices for a 500sqft walkable Parisin style apartment. Nor do they want a xx billion dollar metro cost tacked onto their property tax.
No, a private citizen does not have the ability to demolish entire neighborhoods to create a new New York City with a beautiful Central Park.
Maybe if they own a home, maybe they'd donate their home to some developer to make a community garden. You and I know, that many people would love to do such a thing. But, 99% of people, would reject doing this or demand an infeasible amount of money for this.