Ok, but say you are parent and want what's best for your future kid. It's better for your child that you be #34 partner of Bill Gates, than #1 partner of Joe Jobless. Now apply that realization to everyone.
Soon, only the wealthiest will be able to find partners.
One way would be to raise kids in commune, but even then a super rich commune will beat any other. They would have access to best medical care, the best trainers, the best pretty much everything.