> Whatever will we do when there are already enough houses for everyone to have one?

In many places in Europe and Asia, the govt will essentially pay you to go live in near-abandoned villages and revitalize them.

In USA it’s just ghost towns. See also Detroit

The problem is better described as "There aren't enough homes where people want to live". We have plenty of houses, even in america. The "where people want to live" part largely comes down to density, zoning laws, and the fact that for most people their primary residence represents their entire net worth and it would be materially impactful if the price went down (by building more/better homes nearby). So everyone resists building.

But it's okay, if you resist building for long enough then your town will eventually collapse and your house will be worth nothing anyway. Many american Towns are essentially insolvent and can't afford realistic upkeep prices for services like sewage, roads, good schools, etc., and are living on borrowed time until infrastructure collapses and nobody wants to buy there. See Strong Towns the book.

> The "where people want to live" part largely comes down to density, zoning laws, and the fact that for most people their primary residence represents their entire net worth and it would be materially impactful if the price went down (by building more/better homes nearby).

Infrastructure is a major deal. You can't really exist as a member of modern society without broadband Internet, unless you're Amish or whatever and even they have begun to shift attitudes. Starlink changed the calculation quite a bit, and it definitely helps, but other things such as cellphone reception and emergency services that arrive in a reasonable time are also important.