Exactly. Do people want to live in desirable areas? Absolutely. The much bigger draw to expensive metros, however, are the vastly more robust job prospects that come with those areas.

In a city, you have both much better chances of finding employment suited to your skills specifically, better chances of being paid well for it, and better chances of upwards mobility. Plus, should it become necessary you're more likely to be able to find something to keep the bills paid with even if it's not what you'd like to be doing.

Low CoL areas by contrast come with scant employment that's generally poorly compensated and almost always has a low ceiling.

In some cases one can commute into the city for work and live in LCoL area, but then you're burning time — multiple hours each day, usually — that you'll never get back on your employer instead of yourself or with your family, plus the myriad expenses that come with driving that far and often.