There’s a big difference between owning land and owning real estate in France. Land just isn’t very profitable. People who own fields for example find that renting out fields for grazing isn’t even worth the trouble because of the taxes. If you own an empty field and some weeds or encroach on your neighbor’s property, you’re responsible for getting the weeds off of their land. Real estate on the other hand is quite different. You can rent out apartments in deplorable condition and no one bats a lid – for example renters are responsible for having their own insurance – so if an apartment springs a leak when a renter is living there, his or her insurance must pay for the leak.
If you look at the history of feudalism – you can see how the concept simply moved from outdoors to indoors – behind closed doors. From the country to the cities.
Maybe that is the real reason why every inch of open space will eventually turn into housing developments!