I don't think any of my coworkers have cell phone area codes from the city where we work. Area codes in my age group (25-40 years old) are usually a prestige indicator of where you're from, rather than where you currently live.
How much of it is prestige versus the convenience of not having to change numbers? I have the same cell number from an area code that I moved away from over a decade ago. It's nice knowing that anyone who calls(not counting spam calls) either is meaning to get me or is the rare misdial.
If it's a prestige indicator, people should move their numbers to better zip codes.