It’s a real shame that Phoenix metro is going to ruin everything for Flagstaff and Tucson in the not-too-distant future by refusing to implement any light limits at all.
Dark skies require a pretty high radius of dark landmass. For an estimate of the extent of this, try seeing the areas around major cities here: https://www.lightpollutionmap.info/
I live in Dallas-Fort Worth and grew up near Amarillo, TX. In high school I regularly drove a few miles (like less than 5) away from the city to look at lights. I've noticed in DFW you've got to get much much further away from the city. I can't really put a number on it, but I know even 20 miles out of town you can still only see the brightest stars.
Former astronomer here. From Mt. Graham in Arizona you can see the sky glow from Los Angeles. Phoenix is a lot closer than that.