I think there are two key moves: one is removing the subsidies for private car usage so the true costs are more visible and people can make better choices (c.f. The High Cost of Free Parking), and another would be removing low-density requirements – most expensive cities could increase density rapidly if, say, every homeowner had the ability by-right to add an ADU or convert a single house into a multi-family without decades of recreational lawsuits from the neighborhood NIMBYs. Anywhere built before 1950 probably has a bunch of neighborhoods with little business zones which are marginally profitable because there isn’t quite enough local business but would do well if the density went up by 20-30%, and the profits would probably encourage a virtuous cycle of other neighbors upgrading.