Even regarding Texas, about 16 million of those 27 million live in just 4 metro areas (Dallas, Houston, Austin, San Antonio). Most of the the development, large metros included, is in the eastern half which is a fair bit less arid. Texas has 8 counties that make the top 50 least populous counties by density (https://en.wikipedia.org/wiki/County_statistics_of_the_Unite...).

It fits a pattern that also fits Australia and Canada... people don't want to live as much where it is extremely dry, or extremely hot / cold.