The solution to the urban housing crisis was, continues to be, and will be until its done the building of more housing. A lot more. Density, at every price. Without mandated parking, without vertical clearance limits, without per-unit size limits, without the ability for NIMBYs to stall out or shut down expansion efforts for their own personal gain. Nothing else will cure the ailment - all else is just treating the wound.
Unfortunately, for the past century the larger cities have been steadily sucking their population and talent away. Hub and spoke rail systems are an excellent way to revitalize these towns and encourage population balancing.
Because not everyone wants to live in a Singaporean econobox.
Traditionally, the limitation on this has been weakness / corruption of local government vs the major freight railroads.
Amtrak, with proper Congressional support, could play an interesting part in reopening existing rail to passenger traffic.
Regular, daily train service would revitalize and open up a lot of smaller communities.
Precisely as major cities are grappling with housing and affordability issues.