With seven billion people on the planet, the chances that a girl in Peoria IL would find her "one" in the next town over Moline IL is silly. Statistically its much more likely that her "one" is living in India or in China...
I think this is a statistically invalid argument.
Given the cultural barriers, language, faith, familiarity, mores, beliefs and more that factor into each human personality... the likelihood of another person being a good match drops dramatically with distance.
Folks from too disparate a background are unlikely to mesh well.
A man who has never been farther than 100 miles from the midwestern rural town in which he was born is highly unlikely to be a good match for a woman born down the street who moved around as a child and has traveled the world.
Not impossible... but with each difference in experience and exposure to other ideas, the chances of a great mating decline.
In that sense... the More a person matches your own worldview, your own political view, your own spiritual view, your own intellectual view, and your own emotional disposition... the more likely they are to be "the one".
So the billions don't really factor.
People only come in a fairly narrow range of a few character types. Ranges of smarts, self interest, empathy, and what not. A few dozen different mixes of makeup.
Most of the difference between us are cultural and experiential.
That's why so many long lived marriages are between people who grew up in the same town, went to the same school.
Its when we have mismatched expectations of each other that the resentments build.