The backside line is that the date DATEDIF formula is a safer and simpler choice when the aim is to report age in entire years. Note start and end dates remain the same in all three DATEDIFs; solely the unit is changed. This formulation will return Michael Chang’s age on January 1, 2022, which is 20.
Carbon-14 is radioactive, with a half-life of about 5,700 years. Thus the overall pattern, that males are older—and only somewhat older—seems to stand, making age-gap relationships uncommon. The “best” three-ish-year age hole with males older than ladies, observed cross-culturally, might replicate its uDates optimal selective fitness.