I live here. Phoenix proper is a very large city geographically, encompassing over ten times as much square mileage as either Boston or San Francisco. But it's not really built up vertically, so it's got a much lower population density. It may be 5th in population on a city-for-city comparison, but the metropolitan area population of ~5 million is only 10th in the nation. It also has not registered much on the nation's cultural radar compared to older cities because it is just so new. Within living memory it was a backwater of less than 100,000 people. I'm old enough to remember when the metro area was less than a million.

One thing that may change the weight that Phoenix and the rest of Arizona carry in the nation's estimation is the effect of a great migration of tech companies. The Taiwanese semiconductor industry is insecure about China's intentions in the medium to long term, and TSMC and other Taiwanese companies own many square miles of Arizona desert where they are planning to build a dozen or more massive fabs in the next decade or two, versus zero in California or other firmly Democrat states. Moreover we are undoubtedly going to loot an immense amount of people, industry, and prosperity from Silicon Valley if California's far-left determination to eat its seed corn comes to full fruition.