If no housing is built that’s good for landlords and property owners as rents and property prices rise. If no (affordable) housing is built in an area with strong economic growth that’s good for fundraising of some charities as the problem gets worse.
Enough housing will make all housing affordable anyway.
No economic incentive, more of a sense of responsibility to society and some nationalism. look at the UAE where the incentive is more political or for prestige.
Wait how is raising housing prices responsible for society or nationalistic? Shafting the youth, turning them against the system and reducing their economic output, seems the opposite.