I suspect I can get a larger variety of ethnic food of very decent quality in 1 hour in NYC than in 99% of suburbs.

Shopping for large items, or large quantities, definitely tends to use suburban land because it's cheaper, and a shopping center uses a lot of it. The cost for the customers is the time to drive there.

I can't speak to NYC - best case it would take me 4 hours to get there (.5 to the airport, 1 hour security, 2 hours on the plane, .5 from ny airport to the city). Meanwhile I can get to nearly anywhere in my entire MSA in less than an hour, both city and suburbs (and even a few farms). Within that the majority of ethnic food is in suburbs, though the largest concentration is still downtown.

Well, NYC is NYC.

I live in Baltimore, and if you ask after Chinese, Korean, Indian, or Vietnamese, without specifying city limits, you will be directed to a place in the suburbs with a parking lot (I think this is essentially true of DC as well).