It's worth noting that the percentage of men in the population who were actively reproducing has varied a lot through prehistory and history.

With the advent of agriculture a much smaller percentage of men were able to reproduce than previously, and it remained that way for a long time.

• https://psmag.com/environment/17-to-1-reproductive-success
  

Once upon a time, 4,000 to 8,000 years after humanity invented agriculture, something very strange happened to human reproduction. Across the globe, for every 17 women who were reproducing, passing on genes that are still around today—only one man did the same.

"It wasn't like there was a mass death of males. They were there, so what were they doing?" asks Melissa Wilson Sayres, a computational biologist at Arizona State University, and a member of a group of scientists who uncovered this moment in prehistory by analyzing modern genes.

Another member of the research team, a biological anthropologist, hypothesizes that somehow, only a few men accumulated lots of wealth and power, leaving nothing for others. These men could then pass their wealth on to their sons, perpetuating this pattern of elitist reproductive success. Then, as more thousands of years passed, the numbers of men reproducing, compared to women, rose again. "Maybe more and more people started being successful," Wilson Sayres says. In more recent history, as a global average, about four or five women reproduced for every one man.

Here's the research paper:

• Karmin, et al 2015 A recent bottleneck of Y chromosome diversity coincides with a global change in culture