I think this is only half of the story. There are still lots of affordable houses - in parts of the country that no one wants to live anymore. The value of my sibling's property in Illinois has barely kept up with inflation. So I think some of the national statistics about house prices vs number of units are a bit misleading. We're increasingly paying a premium because we are increasingly concentrating where we want…
It reminds me of some politician in the south whining about people leaving the state (to get to the coast). And he wished silicon valley would "come to real America to create jobs here too".
Of course, as you guessed it, it was one of the deep red states and we all can guess why people were leaving.