Bait & switch, though.
“All it takes is for one to work out.” is not the same as "You just need the one [job] that’s the right fit." or "You just need the one [house] that feels like home." or "You just need the one [life partner]."
Author's examples are, spiritually, the opposite of their friend's advice - in fact, "all it takes is for one to work out" is something often said to people who lost hope because they got lost being too picky.