less than 10% of the world’s inhabitable lands have been settled and inhabited- we are not ever going to be overpopulated- just because certain popular areas are crowded doesn’t mean there isn’t plenty of land for folks to live on- the fact is, they don’t want to give up their billions of acres of state parks and national parks
All the good areas, not wind swept plains, or on the sides of mountains, are all spoken for and or owned by others.
The rest is wind blown tundra, swamps, harsh climates etc...
If we could come up with abundant cheap energy, we could desalinate sea water on a large scale and make a lot of unproductive desert land inhabitable. About 20% of the land is desert not counting the poles.