I don't believe survival of the fit applies to humans anymore.
In some cases women, androgynous men, and physically weak people are in positions of power. Many of the most physically fit
are in prisons, the military, training in attempts for fame in the octagon/ring/whatever the hell people fight in these days, working
manual labor, etc.
Because of human compassion, we help the weak and enable their survival.
Many that are most fit for survival (high intelligence, ability to adapt, good physical shape, etc) are not reproducing because in many
cases that is the more responsible thing to do with one's life....... making them a failure as an organism, but a success at
the 'life' we have created and try to excel at.
There was a time when physically dominating others (or groups of others) while competing for resources and ensuring a number of male heirs
was the only purpose of life, much like animals.