well,zakir naik proved that, if no female womb is killed before birth, number of woman would cross number of male. you can watch that video on youtube.
girls have a strong immune system, so little of the boys can survive till youth.
statistics says,around 20% males maintain secret relationship. if Allah prohibited polygamy 20% male would burn in hell.
as men are supersex,they feel strong attraction to women.
Allah is very kind. He allowed polygamy, so that no male get close to zina.
Allah has made ruling of sex easy on men. nevertheless, if any male get involved into zina,just imagine what the punishment would be.
on the other hand,if a man ignores the call of a wealthy woman,Allah would give him place under his arsh on the judgement day.
So, males are undergoing a test. they have control their sexual desire. if they succeed, they will be rewarded, else punished severely.
May Allah bless us.