Of course they don't talk about the elephant in the room, which is that the cities in question are almost always deep blue shitholes even when they're smack in the middle of deep red states. That means higher crime, more bullshit laws and regulations, and the high density housing the left is all determined to pack us into. It's just a lower quality of life. The article does touch on some minor things that exacerbate the problem, but it dodges the main problem which is shitty governance.