It's been mentioned on here before, but r/K selection theory backs this up pretty substantially.
Biologically, men seek women who have the most fertility, and women seek men who can provide resources.
Historically, women took care of children so the most attractive man is the one who can provide the most.
Men who were providers can their pick of the females and picked the most fertile to perpetuate their genetics.
The Alpha in the office has more resources than the Beta at home.
The 22-year old blonde down the street is more fertile than your 40ish wife.
This is basic biology.