Up until 5 minutes ago, 'stable housing' meant living with your parents and then the neighbourhood where you grew up surrounded by an extensive support network of people you knew you could trust. No 'housing policy' or government required.
You'd need to ship cultural change to make it culturally acceptable to live with your parents in your 30s. It's not happening soon. People would rather live in rental or mortgage stress than engage in strange lifestyles that confer low status. I wish Western culture didn't have such sicknesses, but it does.
Maybe living with parents was the norm where you're from, but in the Paris basin, the low countries and England, from late Medieval times the life pattern was to leave your parents' home as a teenager and work for several years in another household/enterprise until you could afford to form your own household.
Leaving home early is deeply ingrained in Anglo culture.
The UK has had housing policy since WW2, balancing the competing objectives of trying to replace the large amounts of housing destroyed in the war with the dislike of urban sprawl into farmland.
