I believe a majority in the US lives in a metro area of at least 100,000 people, but only about 30% appear to live in a city of at least 100,000 people.
I think the difference is the suburbs, and I don't think that is a recent thing.
https://en.wikipedia.org/wiki/List_of_United_States_cities_b...
https://en.wikipedia.org/wiki/List_of_metropolitan_statistic...
You have:
1. Legal boundaries of cities, which are dependent on the state. Each state has a constitution that determines what the requirements are to be a city. Maybe it's only 10 signatures and filing fee. Maybe it's much more. There is also a well defined process for extending the boundaries. Outside the city you have unincorporated areas, but that's like places where you have to get water from a well and use a septic tank. That's not suburbs, it's country.
2. Because 1) is so random, government statistics office come up with their own definition of "statistical areas". There are metro-statistical area, and micro-statistical areas, and even these depend on which agency made the list.
3. Realtors keep their own definitions.
4. Things like advertisers and business have their own definitions depending on industry (e.g. media markets)
5. locals have their own definition.
At the end of the day, you have to pick a list and work with it, knowing the pros and cons and how that affects your methodology.
I think it's easy to overestimate how much you know about other states.
In New York State, a "town" seems to be not exactly a town, like a stereotypical "small town".
I've lived here most of my life and never really realized, but according to Wikipedia, a "town" in NY is more or less the equivalent to a "township" and within it are "villages".
https://en.wikipedia.org/wiki/Administrative_divisions_of_Ne...
"every piece of land in the State is part of a city or town, which, with the exception of the city of Geneva, is part of one and only one county. Not every piece is in a village or city. A village is part of a town; cities are not part of towns, but have the powers of towns. A village can be a part of more than one town. A village cannot be part of a city."
So more like a division of a county that's not part of a city than an actual town.
And where this is going, is that I think this is where a lot of people live, rather than cities per se.
An administrative division, where a lot of people live, that's neither a city nor a village, but has water and sewer and so on, sounds to me like almost a definition of suburbs.
Eventually, even American multi-millionaires will get bored of buying $7M houses in LA and go fuck off to Phoenix, so who needs to live there and service them?