That’s only true if you are in a competitive market. There is a whole swath of land in flyover country and rural America where it can take awhile to sell a house.
Outside cities, yes, but there also aren't many houses there.
In flyover country, in the cities, it's been "OMG, this house just came on the market four hours ago... quick, send a full offer! Damnit, they already sold it for $20k over asking, again?!?!" for years, only letting up recently.
[EDIT] And I don't just mean like Chicago and Minneapolis, either—any metro area a million or larger, it's probably been like that, and even in some of the smaller ones.
Is that still the case? I feel like rural markets have really boomed in the last few years. At least I'm seeing that in the southeast. Maybe "flyover country" is different.
I mean yes, it's sort of tautological that if you are trying to sell a home in a place very few people want to live, it might be (but isn't by definition!) harder to sell than someplace where a lot of people want to live.